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+---
+name: d3-viz
+description: Creating interactive data visualisations using d3.js. This skill should be used when creating custom charts, graphs, network diagrams, geographic visualisations, or any complex SVG-based data visualisation that requires fine-grained control over visual elements, transitions, or interactions. Use this for bespoke visualisations beyond standard charting libraries, whether in React, Vue, Svelte, vanilla JavaScript, or any other environment.
+---
+
+# D3.js Visualisation
+
+## Overview
+
+This skill provides guidance for creating sophisticated, interactive data visualisations using d3.js. D3.js (Data-Driven Documents) excels at binding data to DOM elements and applying data-driven transformations to create custom, publication-quality visualisations with precise control over every visual element. The techniques work across any JavaScript environment, including vanilla JavaScript, React, Vue, Svelte, and other frameworks.
+
+## When to use d3.js
+
+**Use d3.js for:**
+- Custom visualisations requiring unique visual encodings or layouts
+- Interactive explorations with complex pan, zoom, or brush behaviours
+- Network/graph visualisations (force-directed layouts, tree diagrams, hierarchies, chord diagrams)
+- Geographic visualisations with custom projections
+- Visualisations requiring smooth, choreographed transitions
+- Publication-quality graphics with fine-grained styling control
+- Novel chart types not available in standard libraries
+
+**Consider alternatives for:**
+- 3D visualisations - use Three.js instead
+
+## Core workflow
+
+### 1. Set up d3.js
+
+Import d3 at the top of your script:
+
+```javascript
+import * as d3 from 'd3';
+```
+
+Or use the CDN version (7.x):
+
+```html
+<script src="https://d3js.org/d3.v7.min.js"></script>
+```
+
+All modules (scales, axes, shapes, transitions, etc.) are accessible through the `d3` namespace.
+
+### 2. Choose the integration pattern
+
+**Pattern A: Direct DOM manipulation (recommended for most cases)**
+Use d3 to select DOM elements and manipulate them imperatively. This works in any JavaScript environment:
+
+```javascript
+function drawChart(data) {
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart'); // Select by ID, class, or DOM element
+
+  // Clear previous content
+  svg.selectAll("*").remove();
+
+  // Set up dimensions
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+
+  // Create scales, axes, and draw visualisation
+  // ... d3 code here ...
+}
+
+// Call when data changes
+drawChart(myData);
+```
+
+**Pattern B: Declarative rendering (for frameworks with templating)**
+Use d3 for data calculations (scales, layouts) but render elements via your framework:
+
+```javascript
+function getChartElements(data) {
+  const xScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.value)])
+    .range([0, 400]);
+
+  return data.map((d, i) => ({
+    x: 50,
+    y: i * 30,
+    width: xScale(d.value),
+    height: 25
+  }));
+}
+
+// In React: {getChartElements(data).map((d, i) => <rect key={i} {...d} fill="steelblue" />)}
+// In Vue: v-for directive over the returned array
+// In vanilla JS: Create elements manually from the returned data
+```
+
+Use Pattern A for complex visualisations with transitions, interactions, or when leveraging d3's full capabilities. Use Pattern B for simpler visualisations or when your framework prefers declarative rendering.
+
+### 3. Structure the visualisation code
+
+Follow this standard structure in your drawing function:
+
+```javascript
+function drawVisualization(data) {
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart'); // Or pass a selector/element
+  svg.selectAll("*").remove(); // Clear previous render
+
+  // 1. Define dimensions
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+
+  // 2. Create main group with margins
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+
+  // 3. Create scales
+  const xScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.x)])
+    .range([0, innerWidth]);
+
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.y)])
+    .range([innerHeight, 0]); // Note: inverted for SVG coordinates
+
+  // 4. Create and append axes
+  const xAxis = d3.axisBottom(xScale);
+  const yAxis = d3.axisLeft(yScale);
+
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(xAxis);
+
+  g.append("g")
+    .call(yAxis);
+
+  // 5. Bind data and create visual elements
+  g.selectAll("circle")
+    .data(data)
+    .join("circle")
+    .attr("cx", d => xScale(d.x))
+    .attr("cy", d => yScale(d.y))
+    .attr("r", 5)
+    .attr("fill", "steelblue");
+}
+
+// Call when data changes
+drawVisualization(myData);
+```
+
+### 4. Implement responsive sizing
+
+Make visualisations responsive to container size:
+
+```javascript
+function setupResponsiveChart(containerId, data) {
+  const container = document.getElementById(containerId);
+  const svg = d3.select(`#${containerId}`).append('svg');
+
+  function updateChart() {
+    const { width, height } = container.getBoundingClientRect();
+    svg.attr('width', width).attr('height', height);
+
+    // Redraw visualisation with new dimensions
+    drawChart(data, svg, width, height);
+  }
+
+  // Update on initial load
+  updateChart();
+
+  // Update on window resize
+  window.addEventListener('resize', updateChart);
+
+  // Return cleanup function
+  return () => window.removeEventListener('resize', updateChart);
+}
+
+// Usage:
+// const cleanup = setupResponsiveChart('chart-container', myData);
+// cleanup(); // Call when component unmounts or element removed
+```
+
+Or use ResizeObserver for more direct container monitoring:
+
+```javascript
+function setupResponsiveChartWithObserver(svgElement, data) {
+  const observer = new ResizeObserver(() => {
+    const { width, height } = svgElement.getBoundingClientRect();
+    d3.select(svgElement)
+      .attr('width', width)
+      .attr('height', height);
+
+    // Redraw visualisation
+    drawChart(data, d3.select(svgElement), width, height);
+  });
+
+  observer.observe(svgElement.parentElement);
+  return () => observer.disconnect();
+}
+```
+
+## Common visualisation patterns
+
+### Bar chart
+
+```javascript
+function drawBarChart(data, svgElement) {
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select(svgElement);
+  svg.selectAll("*").remove();
+
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+
+  const xScale = d3.scaleBand()
+    .domain(data.map(d => d.category))
+    .range([0, innerWidth])
+    .padding(0.1);
+
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.value)])
+    .range([innerHeight, 0]);
+
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(d3.axisBottom(xScale));
+
+  g.append("g")
+    .call(d3.axisLeft(yScale));
+
+  g.selectAll("rect")
+    .data(data)
+    .join("rect")
+    .attr("x", d => xScale(d.category))
+    .attr("y", d => yScale(d.value))
+    .attr("width", xScale.bandwidth())
+    .attr("height", d => innerHeight - yScale(d.value))
+    .attr("fill", "steelblue");
+}
+
+// Usage:
+// drawBarChart(myData, document.getElementById('chart'));
+```
+
+### Line chart
+
+```javascript
+const line = d3.line()
+  .x(d => xScale(d.date))
+  .y(d => yScale(d.value))
+  .curve(d3.curveMonotoneX); // Smooth curve
+
+g.append("path")
+  .datum(data)
+  .attr("fill", "none")
+  .attr("stroke", "steelblue")
+  .attr("stroke-width", 2)
+  .attr("d", line);
+```
+
+### Scatter plot
+
+```javascript
+g.selectAll("circle")
+  .data(data)
+  .join("circle")
+  .attr("cx", d => xScale(d.x))
+  .attr("cy", d => yScale(d.y))
+  .attr("r", d => sizeScale(d.size)) // Optional: size encoding
+  .attr("fill", d => colourScale(d.category)) // Optional: colour encoding
+  .attr("opacity", 0.7);
+```
+
+### Chord diagram
+
+A chord diagram shows relationships between entities in a circular layout, with ribbons representing flows between them:
+
+```javascript
+function drawChordDiagram(data) {
+  // data format: array of objects with source, target, and value
+  // Example: [{ source: 'A', target: 'B', value: 10 }, ...]
+
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart');
+  svg.selectAll("*").remove();
+
+  const width = 600;
+  const height = 600;
+  const innerRadius = Math.min(width, height) * 0.3;
+  const outerRadius = innerRadius + 30;
+
+  // Create matrix from data
+  const nodes = Array.from(new Set(data.flatMap(d => [d.source, d.target])));
+  const matrix = Array.from({ length: nodes.length }, () => Array(nodes.length).fill(0));
+
+  data.forEach(d => {
+    const i = nodes.indexOf(d.source);
+    const j = nodes.indexOf(d.target);
+    matrix[i][j] += d.value;
+    matrix[j][i] += d.value;
+  });
+
+  // Create chord layout
+  const chord = d3.chord()
+    .padAngle(0.05)
+    .sortSubgroups(d3.descending);
+
+  const arc = d3.arc()
+    .innerRadius(innerRadius)
+    .outerRadius(outerRadius);
+
+  const ribbon = d3.ribbon()
+    .source(d => d.source)
+    .target(d => d.target);
+
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10)
+    .domain(nodes);
+
+  const g = svg.append("g")
+    .attr("transform", `translate(${width / 2},${height / 2})`);
+
+  const chords = chord(matrix);
+
+  // Draw ribbons
+  g.append("g")
+    .attr("fill-opacity", 0.67)
+    .selectAll("path")
+    .data(chords)
+    .join("path")
+    .attr("d", ribbon)
+    .attr("fill", d => colourScale(nodes[d.source.index]))
+    .attr("stroke", d => d3.rgb(colourScale(nodes[d.source.index])).darker());
+
+  // Draw groups (arcs)
+  const group = g.append("g")
+    .selectAll("g")
+    .data(chords.groups)
+    .join("g");
+
+  group.append("path")
+    .attr("d", arc)
+    .attr("fill", d => colourScale(nodes[d.index]))
+    .attr("stroke", d => d3.rgb(colourScale(nodes[d.index])).darker());
+
+  // Add labels
+  group.append("text")
+    .each(d => { d.angle = (d.startAngle + d.endAngle) / 2; })
+    .attr("dy", "0.31em")
+    .attr("transform", d => `rotate(${(d.angle * 180 / Math.PI) - 90})translate(${outerRadius + 30})${d.angle > Math.PI ? "rotate(180)" : ""}`)
+    .attr("text-anchor", d => d.angle > Math.PI ? "end" : null)
+    .text((d, i) => nodes[i])
+    .style("font-size", "12px");
+}
+```
+
+### Heatmap
+
+A heatmap uses colour to encode values in a two-dimensional grid, useful for showing patterns across categories:
+
+```javascript
+function drawHeatmap(data) {
+  // data format: array of objects with row, column, and value
+  // Example: [{ row: 'A', column: 'X', value: 10 }, ...]
+
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart');
+  svg.selectAll("*").remove();
+
+  const width = 800;
+  const height = 600;
+  const margin = { top: 100, right: 30, bottom: 30, left: 100 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+
+  // Get unique rows and columns
+  const rows = Array.from(new Set(data.map(d => d.row)));
+  const columns = Array.from(new Set(data.map(d => d.column)));
+
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+
+  // Create scales
+  const xScale = d3.scaleBand()
+    .domain(columns)
+    .range([0, innerWidth])
+    .padding(0.01);
+
+  const yScale = d3.scaleBand()
+    .domain(rows)
+    .range([0, innerHeight])
+    .padding(0.01);
+
+  // Colour scale for values
+  const colourScale = d3.scaleSequential(d3.interpolateYlOrRd)
+    .domain([0, d3.max(data, d => d.value)]);
+
+  // Draw rectangles
+  g.selectAll("rect")
+    .data(data)
+    .join("rect")
+    .attr("x", d => xScale(d.column))
+    .attr("y", d => yScale(d.row))
+    .attr("width", xScale.bandwidth())
+    .attr("height", yScale.bandwidth())
+    .attr("fill", d => colourScale(d.value));
+
+  // Add x-axis labels
+  svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`)
+    .selectAll("text")
+    .data(columns)
+    .join("text")
+    .attr("x", d => xScale(d) + xScale.bandwidth() / 2)
+    .attr("y", -10)
+    .attr("text-anchor", "middle")
+    .text(d => d)
+    .style("font-size", "12px");
+
+  // Add y-axis labels
+  svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`)
+    .selectAll("text")
+    .data(rows)
+    .join("text")
+    .attr("x", -10)
+    .attr("y", d => yScale(d) + yScale.bandwidth() / 2)
+    .attr("dy", "0.35em")
+    .attr("text-anchor", "end")
+    .text(d => d)
+    .style("font-size", "12px");
+
+  // Add colour legend
+  const legendWidth = 20;
+  const legendHeight = 200;
+  const legend = svg.append("g")
+    .attr("transform", `translate(${width - 60},${margin.top})`);
+
+  const legendScale = d3.scaleLinear()
+    .domain(colourScale.domain())
+    .range([legendHeight, 0]);
+
+  const legendAxis = d3.axisRight(legendScale)
+    .ticks(5);
+
+  // Draw colour gradient in legend
+  for (let i = 0; i < legendHeight; i++) {
+    legend.append("rect")
+      .attr("y", i)
+      .attr("width", legendWidth)
+      .attr("height", 1)
+      .attr("fill", colourScale(legendScale.invert(i)));
+  }
+
+  legend.append("g")
+    .attr("transform", `translate(${legendWidth},0)`)
+    .call(legendAxis);
+}
+```
+
+### Pie chart
+
+```javascript
+const pie = d3.pie()
+  .value(d => d.value)
+  .sort(null);
+
+const arc = d3.arc()
+  .innerRadius(0)
+  .outerRadius(Math.min(width, height) / 2 - 20);
+
+const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+
+const g = svg.append("g")
+  .attr("transform", `translate(${width / 2},${height / 2})`);
+
+g.selectAll("path")
+  .data(pie(data))
+  .join("path")
+  .attr("d", arc)
+  .attr("fill", (d, i) => colourScale(i))
+  .attr("stroke", "white")
+  .attr("stroke-width", 2);
+```
+
+### Force-directed network
+
+```javascript
+const simulation = d3.forceSimulation(nodes)
+  .force("link", d3.forceLink(links).id(d => d.id).distance(100))
+  .force("charge", d3.forceManyBody().strength(-300))
+  .force("center", d3.forceCenter(width / 2, height / 2));
+
+const link = g.selectAll("line")
+  .data(links)
+  .join("line")
+  .attr("stroke", "#999")
+  .attr("stroke-width", 1);
+
+const node = g.selectAll("circle")
+  .data(nodes)
+  .join("circle")
+  .attr("r", 8)
+  .attr("fill", "steelblue")
+  .call(d3.drag()
+    .on("start", dragstarted)
+    .on("drag", dragged)
+    .on("end", dragended));
+
+simulation.on("tick", () => {
+  link
+    .attr("x1", d => d.source.x)
+    .attr("y1", d => d.source.y)
+    .attr("x2", d => d.target.x)
+    .attr("y2", d => d.target.y);
+  
+  node
+    .attr("cx", d => d.x)
+    .attr("cy", d => d.y);
+});
+
+function dragstarted(event) {
+  if (!event.active) simulation.alphaTarget(0.3).restart();
+  event.subject.fx = event.subject.x;
+  event.subject.fy = event.subject.y;
+}
+
+function dragged(event) {
+  event.subject.fx = event.x;
+  event.subject.fy = event.y;
+}
+
+function dragended(event) {
+  if (!event.active) simulation.alphaTarget(0);
+  event.subject.fx = null;
+  event.subject.fy = null;
+}
+```
+
+## Adding interactivity
+
+### Tooltips
+
+```javascript
+// Create tooltip div (outside SVG)
+const tooltip = d3.select("body").append("div")
+  .attr("class", "tooltip")
+  .style("position", "absolute")
+  .style("visibility", "hidden")
+  .style("background-color", "white")
+  .style("border", "1px solid #ddd")
+  .style("padding", "10px")
+  .style("border-radius", "4px")
+  .style("pointer-events", "none");
+
+// Add to elements
+circles
+  .on("mouseover", function(event, d) {
+    d3.select(this).attr("opacity", 1);
+    tooltip
+      .style("visibility", "visible")
+      .html(`<strong>${d.label}</strong><br/>Value: ${d.value}`);
+  })
+  .on("mousemove", function(event) {
+    tooltip
+      .style("top", (event.pageY - 10) + "px")
+      .style("left", (event.pageX + 10) + "px");
+  })
+  .on("mouseout", function() {
+    d3.select(this).attr("opacity", 0.7);
+    tooltip.style("visibility", "hidden");
+  });
+```
+
+### Zoom and pan
+
+```javascript
+const zoom = d3.zoom()
+  .scaleExtent([0.5, 10])
+  .on("zoom", (event) => {
+    g.attr("transform", event.transform);
+  });
+
+svg.call(zoom);
+```
+
+### Click interactions
+
+```javascript
+circles
+  .on("click", function(event, d) {
+    // Handle click (dispatch event, update app state, etc.)
+    console.log("Clicked:", d);
+
+    // Visual feedback
+    d3.selectAll("circle").attr("fill", "steelblue");
+    d3.select(this).attr("fill", "orange");
+
+    // Optional: dispatch custom event for your framework/app to listen to
+    // window.dispatchEvent(new CustomEvent('chartClick', { detail: d }));
+  });
+```
+
+## Transitions and animations
+
+Add smooth transitions to visual changes:
+
+```javascript
+// Basic transition
+circles
+  .transition()
+  .duration(750)
+  .attr("r", 10);
+
+// Chained transitions
+circles
+  .transition()
+  .duration(500)
+  .attr("fill", "orange")
+  .transition()
+  .duration(500)
+  .attr("r", 15);
+
+// Staggered transitions
+circles
+  .transition()
+  .delay((d, i) => i * 50)
+  .duration(500)
+  .attr("cy", d => yScale(d.value));
+
+// Custom easing
+circles
+  .transition()
+  .duration(1000)
+  .ease(d3.easeBounceOut)
+  .attr("r", 10);
+```
+
+## Scales reference
+
+### Quantitative scales
+
+```javascript
+// Linear scale
+const xScale = d3.scaleLinear()
+  .domain([0, 100])
+  .range([0, 500]);
+
+// Log scale (for exponential data)
+const logScale = d3.scaleLog()
+  .domain([1, 1000])
+  .range([0, 500]);
+
+// Power scale
+const powScale = d3.scalePow()
+  .exponent(2)
+  .domain([0, 100])
+  .range([0, 500]);
+
+// Time scale
+const timeScale = d3.scaleTime()
+  .domain([new Date(2020, 0, 1), new Date(2024, 0, 1)])
+  .range([0, 500]);
+```
+
+### Ordinal scales
+
+```javascript
+// Band scale (for bar charts)
+const bandScale = d3.scaleBand()
+  .domain(['A', 'B', 'C', 'D'])
+  .range([0, 400])
+  .padding(0.1);
+
+// Point scale (for line/scatter categories)
+const pointScale = d3.scalePoint()
+  .domain(['A', 'B', 'C', 'D'])
+  .range([0, 400]);
+
+// Ordinal scale (for colours)
+const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+```
+
+### Sequential scales
+
+```javascript
+// Sequential colour scale
+const colourScale = d3.scaleSequential(d3.interpolateBlues)
+  .domain([0, 100]);
+
+// Diverging colour scale
+const divScale = d3.scaleDiverging(d3.interpolateRdBu)
+  .domain([-10, 0, 10]);
+```
+
+## Best practices
+
+### Data preparation
+
+Always validate and prepare data before visualisation:
+
+```javascript
+// Filter invalid values
+const cleanData = data.filter(d => d.value != null && !isNaN(d.value));
+
+// Sort data if order matters
+const sortedData = [...data].sort((a, b) => b.value - a.value);
+
+// Parse dates
+const parsedData = data.map(d => ({
+  ...d,
+  date: d3.timeParse("%Y-%m-%d")(d.date)
+}));
+```
+
+### Performance optimisation
+
+For large datasets (>1000 elements):
+
+```javascript
+// Use canvas instead of SVG for many elements
+// Use quadtree for collision detection
+// Simplify paths with d3.line().curve(d3.curveStep)
+// Implement virtual scrolling for large lists
+// Use requestAnimationFrame for custom animations
+```
+
+### Accessibility
+
+Make visualisations accessible:
+
+```javascript
+// Add ARIA labels
+svg.attr("role", "img")
+   .attr("aria-label", "Bar chart showing quarterly revenue");
+
+// Add title and description
+svg.append("title").text("Quarterly Revenue 2024");
+svg.append("desc").text("Bar chart showing revenue growth across four quarters");
+
+// Ensure sufficient colour contrast
+// Provide keyboard navigation for interactive elements
+// Include data table alternative
+```
+
+### Styling
+
+Use consistent, professional styling:
+
+```javascript
+// Define colour palettes upfront
+const colours = {
+  primary: '#4A90E2',
+  secondary: '#7B68EE',
+  background: '#F5F7FA',
+  text: '#333333',
+  gridLines: '#E0E0E0'
+};
+
+// Apply consistent typography
+svg.selectAll("text")
+  .style("font-family", "Inter, sans-serif")
+  .style("font-size", "12px");
+
+// Use subtle grid lines
+g.selectAll(".tick line")
+  .attr("stroke", colours.gridLines)
+  .attr("stroke-dasharray", "2,2");
+```
+
+## Common issues and solutions
+
+**Issue**: Axes not appearing
+- Ensure scales have valid domains (check for NaN values)
+- Verify axis is appended to correct group
+- Check transform translations are correct
+
+**Issue**: Transitions not working
+- Call `.transition()` before attribute changes
+- Ensure elements have unique keys for proper data binding
+- Check that useEffect dependencies include all changing data
+
+**Issue**: Responsive sizing not working
+- Use ResizeObserver or window resize listener
+- Update dimensions in state to trigger re-render
+- Ensure SVG has width/height attributes or viewBox
+
+**Issue**: Performance problems
+- Limit number of DOM elements (consider canvas for >1000 items)
+- Debounce resize handlers
+- Use `.join()` instead of separate enter/update/exit selections
+- Avoid unnecessary re-renders by checking dependencies
+
+## Resources
+
+### references/
+Contains detailed reference materials:
+- `d3-patterns.md` - Comprehensive collection of visualisation patterns and code examples
+- `scale-reference.md` - Complete guide to d3 scales with examples
+- `colour-schemes.md` - D3 colour schemes and palette recommendations
+
+### assets/
+
+Contains boilerplate templates:
+
+- `chart-template.js` - Starter template for basic chart
+- `interactive-template.js` - Template with tooltips, zoom, and interactions
+- `sample-data.json` - Example datasets for testing
+
+These templates work with vanilla JavaScript, React, Vue, Svelte, or any other JavaScript environment. Adapt them as needed for your specific framework.
+
+To use these resources, read the relevant files when detailed guidance is needed for specific visualisation types or patterns.

.claude/skills/d3-viz/assets/chart-template.jsx

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+import { useEffect, useRef, useState } from 'react';
+import * as d3 from 'd3';
+
+function BasicChart({ data }) {
+  const svgRef = useRef();
+  
+  useEffect(() => {
+    if (!data || data.length === 0) return;
+    
+    // Select SVG element
+    const svg = d3.select(svgRef.current);
+    svg.selectAll("*").remove(); // Clear previous content
+    
+    // Define dimensions and margins
+    const width = 800;
+    const height = 400;
+    const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+    const innerWidth = width - margin.left - margin.right;
+    const innerHeight = height - margin.top - margin.bottom;
+    
+    // Create main group with margins
+    const g = svg.append("g")
+      .attr("transform", `translate(${margin.left},${margin.top})`);
+    
+    // Create scales
+    const xScale = d3.scaleBand()
+      .domain(data.map(d => d.label))
+      .range([0, innerWidth])
+      .padding(0.1);
+    
+    const yScale = d3.scaleLinear()
+      .domain([0, d3.max(data, d => d.value)])
+      .range([innerHeight, 0])
+      .nice();
+    
+    // Create and append axes
+    const xAxis = d3.axisBottom(xScale);
+    const yAxis = d3.axisLeft(yScale);
+    
+    g.append("g")
+      .attr("class", "x-axis")
+      .attr("transform", `translate(0,${innerHeight})`)
+      .call(xAxis);
+    
+    g.append("g")
+      .attr("class", "y-axis")
+      .call(yAxis);
+    
+    // Bind data and create visual elements (bars in this example)
+    g.selectAll("rect")
+      .data(data)
+      .join("rect")
+      .attr("x", d => xScale(d.label))
+      .attr("y", d => yScale(d.value))
+      .attr("width", xScale.bandwidth())
+      .attr("height", d => innerHeight - yScale(d.value))
+      .attr("fill", "steelblue");
+    
+    // Optional: Add axis labels
+    g.append("text")
+      .attr("class", "axis-label")
+      .attr("x", innerWidth / 2)
+      .attr("y", innerHeight + margin.bottom - 5)
+      .attr("text-anchor", "middle")
+      .text("Category");
+    
+    g.append("text")
+      .attr("class", "axis-label")
+      .attr("transform", "rotate(-90)")
+      .attr("x", -innerHeight / 2)
+      .attr("y", -margin.left + 15)
+      .attr("text-anchor", "middle")
+      .text("Value");
+    
+  }, [data]);
+  
+  return (
+    <div className="chart-container">
+      <svg 
+        ref={svgRef} 
+        width="800" 
+        height="400"
+        style={{ border: '1px solid #ddd' }}
+      />
+    </div>
+  );
+}
+
+// Example usage
+export default function App() {
+  const sampleData = [
+    { label: 'A', value: 30 },
+    { label: 'B', value: 80 },
+    { label: 'C', value: 45 },
+    { label: 'D', value: 60 },
+    { label: 'E', value: 20 },
+    { label: 'F', value: 90 }
+  ];
+  
+  return (
+    <div className="p-8">
+      <h1 className="text-2xl font-bold mb-4">Basic D3.js Chart</h1>
+      <BasicChart data={sampleData} />
+    </div>
+  );
+}

.claude/skills/d3-viz/assets/interactive-template.jsx

@@ -0,0 +1,227 @@
+import { useEffect, useRef, useState } from 'react';
+import * as d3 from 'd3';
+
+function InteractiveChart({ data }) {
+  const svgRef = useRef();
+  const tooltipRef = useRef();
+  const [selectedPoint, setSelectedPoint] = useState(null);
+  
+  useEffect(() => {
+    if (!data || data.length === 0) return;
+    
+    const svg = d3.select(svgRef.current);
+    svg.selectAll("*").remove();
+    
+    // Dimensions
+    const width = 800;
+    const height = 500;
+    const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+    const innerWidth = width - margin.left - margin.right;
+    const innerHeight = height - margin.top - margin.bottom;
+    
+    // Create main group
+    const g = svg.append("g")
+      .attr("transform", `translate(${margin.left},${margin.top})`);
+    
+    // Scales
+    const xScale = d3.scaleLinear()
+      .domain([0, d3.max(data, d => d.x)])
+      .range([0, innerWidth])
+      .nice();
+    
+    const yScale = d3.scaleLinear()
+      .domain([0, d3.max(data, d => d.y)])
+      .range([innerHeight, 0])
+      .nice();
+    
+    const sizeScale = d3.scaleSqrt()
+      .domain([0, d3.max(data, d => d.size || 10)])
+      .range([3, 20]);
+    
+    const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+    
+    // Add zoom behaviour
+    const zoom = d3.zoom()
+      .scaleExtent([0.5, 10])
+      .on("zoom", (event) => {
+        g.attr("transform", `translate(${margin.left + event.transform.x},${margin.top + event.transform.y}) scale(${event.transform.k})`);
+      });
+    
+    svg.call(zoom);
+    
+    // Axes
+    const xAxis = d3.axisBottom(xScale);
+    const yAxis = d3.axisLeft(yScale);
+    
+    const xAxisGroup = g.append("g")
+      .attr("class", "x-axis")
+      .attr("transform", `translate(0,${innerHeight})`)
+      .call(xAxis);
+    
+    const yAxisGroup = g.append("g")
+      .attr("class", "y-axis")
+      .call(yAxis);
+    
+    // Grid lines
+    g.append("g")
+      .attr("class", "grid")
+      .attr("opacity", 0.1)
+      .call(d3.axisLeft(yScale)
+        .tickSize(-innerWidth)
+        .tickFormat(""));
+    
+    g.append("g")
+      .attr("class", "grid")
+      .attr("opacity", 0.1)
+      .attr("transform", `translate(0,${innerHeight})`)
+      .call(d3.axisBottom(xScale)
+        .tickSize(-innerHeight)
+        .tickFormat(""));
+    
+    // Tooltip
+    const tooltip = d3.select(tooltipRef.current);
+    
+    // Data points
+    const circles = g.selectAll("circle")
+      .data(data)
+      .join("circle")
+      .attr("cx", d => xScale(d.x))
+      .attr("cy", d => yScale(d.y))
+      .attr("r", d => sizeScale(d.size || 10))
+      .attr("fill", d => colourScale(d.category || 'default'))
+      .attr("stroke", "#fff")
+      .attr("stroke-width", 2)
+      .attr("opacity", 0.7)
+      .style("cursor", "pointer");
+    
+    // Hover interactions
+    circles
+      .on("mouseover", function(event, d) {
+        // Enlarge circle
+        d3.select(this)
+          .transition()
+          .duration(200)
+          .attr("opacity", 1)
+          .attr("stroke-width", 3);
+        
+        // Show tooltip
+        tooltip
+          .style("display", "block")
+          .style("left", (event.pageX + 10) + "px")
+          .style("top", (event.pageY - 10) + "px")
+          .html(`
+            <strong>${d.label || 'Point'}</strong><br/>
+            X: ${d.x.toFixed(2)}<br/>
+            Y: ${d.y.toFixed(2)}<br/>
+            ${d.category ? `Category: ${d.category}<br/>` : ''}
+            ${d.size ? `Size: ${d.size.toFixed(2)}` : ''}
+          `);
+      })
+      .on("mousemove", function(event) {
+        tooltip
+          .style("left", (event.pageX + 10) + "px")
+          .style("top", (event.pageY - 10) + "px");
+      })
+      .on("mouseout", function() {
+        // Restore circle
+        d3.select(this)
+          .transition()
+          .duration(200)
+          .attr("opacity", 0.7)
+          .attr("stroke-width", 2);
+        
+        // Hide tooltip
+        tooltip.style("display", "none");
+      })
+      .on("click", function(event, d) {
+        // Highlight selected point
+        circles.attr("stroke", "#fff").attr("stroke-width", 2);
+        d3.select(this)
+          .attr("stroke", "#000")
+          .attr("stroke-width", 3);
+        
+        setSelectedPoint(d);
+      });
+    
+    // Add transition on initial render
+    circles
+      .attr("r", 0)
+      .transition()
+      .duration(800)
+      .delay((d, i) => i * 20)
+      .attr("r", d => sizeScale(d.size || 10));
+    
+    // Axis labels
+    g.append("text")
+      .attr("class", "axis-label")
+      .attr("x", innerWidth / 2)
+      .attr("y", innerHeight + margin.bottom - 5)
+      .attr("text-anchor", "middle")
+      .style("font-size", "14px")
+      .text("X Axis");
+    
+    g.append("text")
+      .attr("class", "axis-label")
+      .attr("transform", "rotate(-90)")
+      .attr("x", -innerHeight / 2)
+      .attr("y", -margin.left + 15)
+      .attr("text-anchor", "middle")
+      .style("font-size", "14px")
+      .text("Y Axis");
+    
+  }, [data]);
+  
+  return (
+    <div className="relative">
+      <svg 
+        ref={svgRef} 
+        width="800" 
+        height="500"
+        style={{ border: '1px solid #ddd', cursor: 'grab' }}
+      />
+      <div
+        ref={tooltipRef}
+        style={{
+          position: 'absolute',
+          display: 'none',
+          padding: '10px',
+          background: 'white',
+          border: '1px solid #ddd',
+          borderRadius: '4px',
+          pointerEvents: 'none',
+          boxShadow: '0 2px 4px rgba(0,0,0,0.1)',
+          fontSize: '13px',
+          zIndex: 1000
+        }}
+      />
+      {selectedPoint && (
+        <div className="mt-4 p-4 bg-blue-50 rounded border border-blue-200">
+          <h3 className="font-bold mb-2">Selected Point</h3>
+          <pre className="text-sm">{JSON.stringify(selectedPoint, null, 2)}</pre>
+        </div>
+      )}
+    </div>
+  );
+}
+
+// Example usage
+export default function App() {
+  const sampleData = Array.from({ length: 50 }, (_, i) => ({
+    id: i,
+    label: `Point ${i + 1}`,
+    x: Math.random() * 100,
+    y: Math.random() * 100,
+    size: Math.random() * 30 + 5,
+    category: ['A', 'B', 'C', 'D'][Math.floor(Math.random() * 4)]
+  }));
+  
+  return (
+    <div className="p-8">
+      <h1 className="text-2xl font-bold mb-2">Interactive D3.js Chart</h1>
+      <p className="text-gray-600 mb-4">
+        Hover over points for details. Click to select. Scroll to zoom. Drag to pan.
+      </p>
+      <InteractiveChart data={sampleData} />
+    </div>
+  );
+}

.claude/skills/d3-viz/assets/sample-data.json

@@ -0,0 +1,115 @@
+{
+  "timeSeries": [
+    { "date": "2024-01-01", "value": 120, "category": "A" },
+    { "date": "2024-02-01", "value": 135, "category": "A" },
+    { "date": "2024-03-01", "value": 128, "category": "A" },
+    { "date": "2024-04-01", "value": 145, "category": "A" },
+    { "date": "2024-05-01", "value": 152, "category": "A" },
+    { "date": "2024-06-01", "value": 168, "category": "A" },
+    { "date": "2024-07-01", "value": 175, "category": "A" },
+    { "date": "2024-08-01", "value": 182, "category": "A" },
+    { "date": "2024-09-01", "value": 190, "category": "A" },
+    { "date": "2024-10-01", "value": 185, "category": "A" },
+    { "date": "2024-11-01", "value": 195, "category": "A" },
+    { "date": "2024-12-01", "value": 210, "category": "A" }
+  ],
+  
+  "categorical": [
+    { "label": "Product A", "value": 450, "category": "Electronics" },
+    { "label": "Product B", "value": 320, "category": "Electronics" },
+    { "label": "Product C", "value": 580, "category": "Clothing" },
+    { "label": "Product D", "value": 290, "category": "Clothing" },
+    { "label": "Product E", "value": 410, "category": "Food" },
+    { "label": "Product F", "value": 370, "category": "Food" }
+  ],
+  
+  "scatterData": [
+    { "x": 12, "y": 45, "size": 25, "category": "Group A", "label": "Point 1" },
+    { "x": 25, "y": 62, "size": 35, "category": "Group A", "label": "Point 2" },
+    { "x": 38, "y": 55, "size": 20, "category": "Group B", "label": "Point 3" },
+    { "x": 45, "y": 78, "size": 40, "category": "Group B", "label": "Point 4" },
+    { "x": 52, "y": 68, "size": 30, "category": "Group C", "label": "Point 5" },
+    { "x": 65, "y": 85, "size": 45, "category": "Group C", "label": "Point 6" },
+    { "x": 72, "y": 72, "size": 28, "category": "Group A", "label": "Point 7" },
+    { "x": 85, "y": 92, "size": 50, "category": "Group B", "label": "Point 8" }
+  ],
+  
+  "hierarchical": {
+    "name": "Root",
+    "children": [
+      {
+        "name": "Category 1",
+        "children": [
+          { "name": "Item 1.1", "value": 100 },
+          { "name": "Item 1.2", "value": 150 },
+          { "name": "Item 1.3", "value": 80 }
+        ]
+      },
+      {
+        "name": "Category 2",
+        "children": [
+          { "name": "Item 2.1", "value": 200 },
+          { "name": "Item 2.2", "value": 120 },
+          { "name": "Item 2.3", "value": 90 }
+        ]
+      },
+      {
+        "name": "Category 3",
+        "children": [
+          { "name": "Item 3.1", "value": 180 },
+          { "name": "Item 3.2", "value": 140 }
+        ]
+      }
+    ]
+  },
+  
+  "network": {
+    "nodes": [
+      { "id": "A", "group": 1 },
+      { "id": "B", "group": 1 },
+      { "id": "C", "group": 1 },
+      { "id": "D", "group": 2 },
+      { "id": "E", "group": 2 },
+      { "id": "F", "group": 3 },
+      { "id": "G", "group": 3 },
+      { "id": "H", "group": 3 }
+    ],
+    "links": [
+      { "source": "A", "target": "B", "value": 1 },
+      { "source": "A", "target": "C", "value": 2 },
+      { "source": "B", "target": "C", "value": 1 },
+      { "source": "C", "target": "D", "value": 3 },
+      { "source": "D", "target": "E", "value": 2 },
+      { "source": "E", "target": "F", "value": 1 },
+      { "source": "F", "target": "G", "value": 2 },
+      { "source": "F", "target": "H", "value": 1 },
+      { "source": "G", "target": "H", "value": 1 }
+    ]
+  },
+  
+  "stackedData": [
+    { "group": "Q1", "seriesA": 30, "seriesB": 40, "seriesC": 25 },
+    { "group": "Q2", "seriesA": 45, "seriesB": 35, "seriesC": 30 },
+    { "group": "Q3", "seriesA": 40, "seriesB": 50, "seriesC": 35 },
+    { "group": "Q4", "seriesA": 55, "seriesB": 45, "seriesC": 40 }
+  ],
+  
+  "geographicPoints": [
+    { "city": "London", "latitude": 51.5074, "longitude": -0.1278, "value": 8900000 },
+    { "city": "Paris", "latitude": 48.8566, "longitude": 2.3522, "value": 2140000 },
+    { "city": "Berlin", "latitude": 52.5200, "longitude": 13.4050, "value": 3645000 },
+    { "city": "Madrid", "latitude": 40.4168, "longitude": -3.7038, "value": 3223000 },
+    { "city": "Rome", "latitude": 41.9028, "longitude": 12.4964, "value": 2873000 }
+  ],
+  
+  "divergingData": [
+    { "category": "Item A", "value": -15 },
+    { "category": "Item B", "value": 8 },
+    { "category": "Item C", "value": -22 },
+    { "category": "Item D", "value": 18 },
+    { "category": "Item E", "value": -5 },
+    { "category": "Item F", "value": 25 },
+    { "category": "Item G", "value": -12 },
+    { "category": "Item H", "value": 14 }
+  ]
+}

.claude/skills/d3-viz/references/colour-schemes.md

@@ -0,0 +1,564 @@
+# D3.js Colour Schemes and Palette Recommendations
+
+Comprehensive guide to colour selection in data visualisation with d3.js.
+
+## Built-in categorical colour schemes
+
+### Category10 (default)
+
+```javascript
+d3.schemeCategory10
+// ['#1f77b4', '#ff7f0e', '#2ca02c', '#d62728', '#9467bd',
+//  '#8c564b', '#e377c2', '#7f7f7f', '#bcbd22', '#17becf']
+```
+
+**Characteristics:**
+- 10 distinct colours
+- Good colour-blind accessibility
+- Default choice for most categorical data
+- Balanced saturation and brightness
+
+**Use cases:** General purpose categorical encoding, legend items, multiple data series
+
+### Tableau10
+
+```javascript
+d3.schemeTableau10
+```
+
+**Characteristics:**
+- 10 colours optimised for data visualisation
+- Professional appearance
+- Excellent distinguishability
+
+**Use cases:** Business dashboards, professional reports, presentations
+
+### Accent
+
+```javascript
+d3.schemeAccent
+// 8 colours with high saturation
+```
+
+**Characteristics:**
+- Bright, vibrant colours
+- High contrast
+- Modern aesthetic
+
+**Use cases:** Highlighting important categories, modern web applications
+
+### Dark2
+
+```javascript
+d3.schemeDark2
+// 8 darker, muted colours
+```
+
+**Characteristics:**
+- Subdued palette
+- Professional appearance
+- Good for dark backgrounds
+
+**Use cases:** Dark mode visualisations, professional contexts
+
+### Paired
+
+```javascript
+d3.schemePaired
+// 12 colours in pairs of similar hues
+```
+
+**Characteristics:**
+- Pairs of light and dark variants
+- Useful for nested categories
+- 12 distinct colours
+
+**Use cases:** Grouped bar charts, hierarchical categories, before/after comparisons
+
+### Pastel1 & Pastel2
+
+```javascript
+d3.schemePastel1 // 9 colours
+d3.schemePastel2 // 8 colours
+```
+
+**Characteristics:**
+- Soft, low-saturation colours
+- Gentle appearance
+- Good for large areas
+
+**Use cases:** Background colours, subtle categorisation, calming visualisations
+
+### Set1, Set2, Set3
+
+```javascript
+d3.schemeSet1 // 9 colours - vivid
+d3.schemeSet2 // 8 colours - muted
+d3.schemeSet3 // 12 colours - pastel
+```
+
+**Characteristics:**
+- Set1: High saturation, maximum distinction
+- Set2: Professional, balanced
+- Set3: Subtle, many categories
+
+**Use cases:** Varied based on visual hierarchy needs
+
+## Sequential colour schemes
+
+Sequential schemes map continuous data from low to high values using a single hue or gradient.
+
+### Single-hue sequential
+
+**Blues:**
+```javascript
+d3.interpolateBlues
+d3.schemeBlues[9] // 9-step discrete version
+```
+
+**Other single-hue options:**
+- `d3.interpolateGreens` / `d3.schemeGreens`
+- `d3.interpolateOranges` / `d3.schemeOranges`
+- `d3.interpolatePurples` / `d3.schemePurples`
+- `d3.interpolateReds` / `d3.schemeReds`
+- `d3.interpolateGreys` / `d3.schemeGreys`
+
+**Use cases:**
+- Simple heat maps
+- Choropleth maps
+- Density plots
+- Single-metric visualisations
+
+### Multi-hue sequential
+
+**Viridis (recommended):**
+```javascript
+d3.interpolateViridis
+```
+
+**Characteristics:**
+- Perceptually uniform
+- Colour-blind friendly
+- Print-safe
+- No visual dead zones
+- Monotonically increasing perceived lightness
+
+**Other perceptually-uniform options:**
+- `d3.interpolatePlasma` - Purple to yellow
+- `d3.interpolateInferno` - Black to white through red/orange
+- `d3.interpolateMagma` - Black to white through purple
+- `d3.interpolateCividis` - Colour-blind optimised
+
+**Colour-blind accessible:**
+```javascript
+d3.interpolateTurbo // Rainbow-like but perceptually uniform
+d3.interpolateCool  // Cyan to magenta
+d3.interpolateWarm  // Orange to yellow
+```
+
+**Use cases:**
+- Scientific visualisation
+- Medical imaging
+- Any high-precision data visualisation
+- Accessible visualisations
+
+### Traditional sequential
+
+**Yellow-Orange-Red:**
+```javascript
+d3.interpolateYlOrRd
+d3.schemeYlOrRd[9]
+```
+
+**Yellow-Green-Blue:**
+```javascript
+d3.interpolateYlGnBu
+d3.schemeYlGnBu[9]
+```
+
+**Other multi-hue:**
+- `d3.interpolateBuGn` - Blue to green
+- `d3.interpolateBuPu` - Blue to purple
+- `d3.interpolateGnBu` - Green to blue
+- `d3.interpolateOrRd` - Orange to red
+- `d3.interpolatePuBu` - Purple to blue
+- `d3.interpolatePuBuGn` - Purple to blue-green
+- `d3.interpolatePuRd` - Purple to red
+- `d3.interpolateRdPu` - Red to purple
+- `d3.interpolateYlGn` - Yellow to green
+- `d3.interpolateYlOrBr` - Yellow to orange-brown
+
+**Use cases:** Traditional data visualisation, familiar colour associations (temperature, vegetation, water)
+
+## Diverging colour schemes
+
+Diverging schemes highlight deviations from a central value using two distinct hues.
+
+### Red-Blue (temperature)
+
+```javascript
+d3.interpolateRdBu
+d3.schemeRdBu[11]
+```
+
+**Characteristics:**
+- Intuitive temperature metaphor
+- Strong contrast
+- Clear positive/negative distinction
+
+**Use cases:** Temperature, profit/loss, above/below average, correlation
+
+### Red-Yellow-Blue
+
+```javascript
+d3.interpolateRdYlBu
+d3.schemeRdYlBu[11]
+```
+
+**Characteristics:**
+- Three-colour gradient
+- Softer transition through yellow
+- More visual steps
+
+**Use cases:** When extreme values need emphasis and middle needs visibility
+
+### Other diverging schemes
+
+**Traffic light:**
+```javascript
+d3.interpolateRdYlGn // Red (bad) to green (good)
+```
+
+**Spectral (rainbow):**
+```javascript
+d3.interpolateSpectral // Full spectrum
+```
+
+**Other options:**
+- `d3.interpolateBrBG` - Brown to blue-green
+- `d3.interpolatePiYG` - Pink to yellow-green
+- `d3.interpolatePRGn` - Purple to green
+- `d3.interpolatePuOr` - Purple to orange
+- `d3.interpolateRdGy` - Red to grey
+
+**Use cases:** Choose based on semantic meaning and accessibility needs
+
+## Colour-blind friendly palettes
+
+### General guidelines
+
+1. **Avoid red-green combinations** (most common colour blindness)
+2. **Use blue-orange diverging** instead of red-green
+3. **Add texture or patterns** as redundant encoding
+4. **Test with simulation tools**
+
+### Recommended colour-blind safe schemes
+
+**Categorical:**
+```javascript
+// Okabe-Ito palette (colour-blind safe)
+const okabePalette = [
+  '#E69F00', // Orange
+  '#56B4E9', // Sky blue
+  '#009E73', // Bluish green
+  '#F0E442', // Yellow
+  '#0072B2', // Blue
+  '#D55E00', // Vermillion
+  '#CC79A7', // Reddish purple
+  '#000000'  // Black
+];
+
+const colourScale = d3.scaleOrdinal()
+  .domain(categories)
+  .range(okabePalette);
+```
+
+**Sequential:**
+```javascript
+// Use Viridis, Cividis, or Blues
+d3.interpolateViridis  // Best overall
+d3.interpolateCividis  // Optimised for CVD
+d3.interpolateBlues    // Simple, safe
+```
+
+**Diverging:**
+```javascript
+// Use blue-orange instead of red-green
+d3.interpolateBrBG
+d3.interpolatePuOr
+```
+
+## Custom colour palettes
+
+### Creating custom sequential
+
+```javascript
+const customSequential = d3.scaleLinear()
+  .domain([0, 100])
+  .range(['#e8f4f8', '#006d9c']) // Light to dark blue
+  .interpolate(d3.interpolateLab); // Perceptually uniform
+```
+
+### Creating custom diverging
+
+```javascript
+const customDiverging = d3.scaleLinear()
+  .domain([0, 50, 100])
+  .range(['#ca0020', '#f7f7f7', '#0571b0']) // Red, grey, blue
+  .interpolate(d3.interpolateLab);
+```
+
+### Creating custom categorical
+
+```javascript
+// Brand colours
+const brandPalette = [
+  '#FF6B6B', // Primary red
+  '#4ECDC4', // Secondary teal
+  '#45B7D1', // Tertiary blue
+  '#FFA07A', // Accent coral
+  '#98D8C8'  // Accent mint
+];
+
+const colourScale = d3.scaleOrdinal()
+  .domain(categories)
+  .range(brandPalette);
+```
+
+## Semantic colour associations
+
+### Universal colour meanings
+
+**Red:**
+- Danger, error, negative
+- High temperature
+- Debt, loss
+
+**Green:**
+- Success, positive
+- Growth, vegetation
+- Profit, gain
+
+**Blue:**
+- Trust, calm
+- Water, cold
+- Information, neutral
+
+**Yellow/Orange:**
+- Warning, caution
+- Energy, warmth
+- Attention
+
+**Grey:**
+- Neutral, inactive
+- Missing data
+- Background
+
+### Context-specific palettes
+
+**Financial:**
+```javascript
+const financialColours = {
+  profit: '#27ae60',
+  loss: '#e74c3c',
+  neutral: '#95a5a6',
+  highlight: '#3498db'
+};
+```
+
+**Temperature:**
+```javascript
+const temperatureScale = d3.scaleSequential(d3.interpolateRdYlBu)
+  .domain([40, -10]); // Hot to cold (reversed)
+```
+
+**Traffic/Status:**
+```javascript
+const statusColours = {
+  success: '#27ae60',
+  warning: '#f39c12',
+  error: '#e74c3c',
+  info: '#3498db',
+  neutral: '#95a5a6'
+};
+```
+
+## Accessibility best practices
+
+### Contrast ratios
+
+Ensure sufficient contrast between colours and backgrounds:
+
+```javascript
+// Good contrast example
+const highContrast = {
+  background: '#ffffff',
+  text: '#2c3e50',
+  primary: '#3498db',
+  secondary: '#e74c3c'
+};
+```
+
+**WCAG guidelines:**
+- Normal text: 4.5:1 minimum
+- Large text: 3:1 minimum
+- UI components: 3:1 minimum
+
+### Redundant encoding
+
+Never rely solely on colour to convey information:
+
+```javascript
+// Add patterns or shapes
+const symbols = ['circle', 'square', 'triangle', 'diamond'];
+
+// Add text labels
+// Use line styles (solid, dashed, dotted)
+// Use size encoding
+```
+
+### Testing
+
+Test visualisations for colour blindness:
+- Chrome DevTools (Rendering > Emulate vision deficiencies)
+- Colour Oracle (free desktop application)
+- Coblis (online simulator)
+
+## Professional colour recommendations
+
+### Data journalism
+
+```javascript
+// Guardian style
+const guardianPalette = [
+  '#005689', // Guardian blue
+  '#c70000', // Guardian red
+  '#7d0068', // Guardian pink
+  '#951c75', // Guardian purple
+];
+
+// FT style
+const ftPalette = [
+  '#0f5499', // FT blue
+  '#990f3d', // FT red
+  '#593380', // FT purple
+  '#262a33', // FT black
+];
+```
+
+### Academic/Scientific
+
+```javascript
+// Nature journal style
+const naturePalette = [
+  '#0071b2', // Blue
+  '#d55e00', // Vermillion
+  '#009e73', // Green
+  '#f0e442', // Yellow
+];
+
+// Use Viridis for continuous data
+const scientificScale = d3.scaleSequential(d3.interpolateViridis);
+```
+
+### Corporate/Business
+
+```javascript
+// Professional, conservative
+const corporatePalette = [
+  '#003f5c', // Dark blue
+  '#58508d', // Purple
+  '#bc5090', // Magenta
+  '#ff6361', // Coral
+  '#ffa600'  // Orange
+];
+```
+
+## Dynamic colour selection
+
+### Based on data range
+
+```javascript
+function selectColourScheme(data) {
+  const extent = d3.extent(data);
+  const hasNegative = extent[0] < 0;
+  const hasPositive = extent[1] > 0;
+  
+  if (hasNegative && hasPositive) {
+    // Diverging: data crosses zero
+    return d3.scaleSequentialSymlog(d3.interpolateRdBu)
+      .domain([extent[0], 0, extent[1]]);
+  } else {
+    // Sequential: all positive or all negative
+    return d3.scaleSequential(d3.interpolateViridis)
+      .domain(extent);
+  }
+}
+```
+
+### Based on category count
+
+```javascript
+function selectCategoricalScheme(categories) {
+  const n = categories.length;
+  
+  if (n <= 10) {
+    return d3.scaleOrdinal(d3.schemeTableau10);
+  } else if (n <= 12) {
+    return d3.scaleOrdinal(d3.schemePaired);
+  } else {
+    // For many categories, use sequential with quantize
+    return d3.scaleQuantize()
+      .domain([0, n - 1])
+      .range(d3.quantize(d3.interpolateRainbow, n));
+  }
+}
+```
+
+## Common colour mistakes to avoid
+
+1. **Rainbow gradients for sequential data**
+   - Problem: Not perceptually uniform, hard to read
+   - Solution: Use Viridis, Blues, or other uniform schemes
+
+2. **Red-green for diverging (colour blindness)**
+   - Problem: 8% of males can't distinguish
+   - Solution: Use blue-orange or purple-green
+
+3. **Too many categorical colours**
+   - Problem: Hard to distinguish and remember
+   - Solution: Limit to 5-8 categories, use grouping
+
+4. **Insufficient contrast**
+   - Problem: Poor readability
+   - Solution: Test contrast ratios, use darker colours on light backgrounds
+
+5. **Culturally inconsistent colours**
+   - Problem: Confusing semantic meaning
+   - Solution: Research colour associations for target audience
+
+6. **Inverted temperature scales**
+   - Problem: Counterintuitive (red = cold)
+   - Solution: Red/orange = hot, blue = cold
+
+## Quick reference guide
+
+**Need to show...**
+
+- **Categories (≤10):** `d3.schemeCategory10` or `d3.schemeTableau10`
+- **Categories (>10):** `d3.schemePaired` or group categories
+- **Sequential (general):** `d3.interpolateViridis`
+- **Sequential (scientific):** `d3.interpolateViridis` or `d3.interpolatePlasma`
+- **Sequential (temperature):** `d3.interpolateRdYlBu` (inverted)
+- **Diverging (zero):** `d3.interpolateRdBu` or `d3.interpolateBrBG`
+- **Diverging (good/bad):** `d3.interpolateRdYlGn` (inverted)
+- **Colour-blind safe (categorical):** Okabe-Ito palette (shown above)
+- **Colour-blind safe (sequential):** `d3.interpolateCividis` or `d3.interpolateBlues`
+- **Colour-blind safe (diverging):** `d3.interpolatePuOr` or `d3.interpolateBrBG`
+
+**Always remember:**
+1. Test for colour-blindness
+2. Ensure sufficient contrast
+3. Use semantic colours appropriately
+4. Add redundant encoding (patterns, labels)
+5. Keep it simple (fewer colours = clearer visualisation)

.claude/skills/d3-viz/references/d3-patterns.md

@@ -0,0 +1,869 @@
+# D3.js Visualisation Patterns
+
+This reference provides detailed code patterns for common d3.js visualisation types.
+
+## Hierarchical visualisations
+
+### Tree diagram
+
+```javascript
+useEffect(() => {
+  if (!data) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 600;
+  
+  const tree = d3.tree().size([height - 100, width - 200]);
+  
+  const root = d3.hierarchy(data);
+  tree(root);
+  
+  const g = svg.append("g")
+    .attr("transform", "translate(100,50)");
+  
+  // Links
+  g.selectAll("path")
+    .data(root.links())
+    .join("path")
+    .attr("d", d3.linkHorizontal()
+      .x(d => d.y)
+      .y(d => d.x))
+    .attr("fill", "none")
+    .attr("stroke", "#555")
+    .attr("stroke-width", 2);
+  
+  // Nodes
+  const node = g.selectAll("g")
+    .data(root.descendants())
+    .join("g")
+    .attr("transform", d => `translate(${d.y},${d.x})`);
+  
+  node.append("circle")
+    .attr("r", 6)
+    .attr("fill", d => d.children ? "#555" : "#999");
+  
+  node.append("text")
+    .attr("dy", "0.31em")
+    .attr("x", d => d.children ? -8 : 8)
+    .attr("text-anchor", d => d.children ? "end" : "start")
+    .text(d => d.data.name)
+    .style("font-size", "12px");
+    
+}, [data]);
+```
+
+### Treemap
+
+```javascript
+useEffect(() => {
+  if (!data) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 600;
+  
+  const root = d3.hierarchy(data)
+    .sum(d => d.value)
+    .sort((a, b) => b.value - a.value);
+  
+  d3.treemap()
+    .size([width, height])
+    .padding(2)
+    .round(true)(root);
+  
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+  
+  const cell = svg.selectAll("g")
+    .data(root.leaves())
+    .join("g")
+    .attr("transform", d => `translate(${d.x0},${d.y0})`);
+  
+  cell.append("rect")
+    .attr("width", d => d.x1 - d.x0)
+    .attr("height", d => d.y1 - d.y0)
+    .attr("fill", d => colourScale(d.parent.data.name))
+    .attr("stroke", "white")
+    .attr("stroke-width", 2);
+  
+  cell.append("text")
+    .attr("x", 4)
+    .attr("y", 16)
+    .text(d => d.data.name)
+    .style("font-size", "12px")
+    .style("fill", "white");
+    
+}, [data]);
+```
+
+### Sunburst diagram
+
+```javascript
+useEffect(() => {
+  if (!data) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 600;
+  const height = 600;
+  const radius = Math.min(width, height) / 2;
+  
+  const root = d3.hierarchy(data)
+    .sum(d => d.value)
+    .sort((a, b) => b.value - a.value);
+  
+  const partition = d3.partition()
+    .size([2 * Math.PI, radius]);
+  
+  partition(root);
+  
+  const arc = d3.arc()
+    .startAngle(d => d.x0)
+    .endAngle(d => d.x1)
+    .innerRadius(d => d.y0)
+    .outerRadius(d => d.y1);
+  
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${width / 2},${height / 2})`);
+  
+  g.selectAll("path")
+    .data(root.descendants())
+    .join("path")
+    .attr("d", arc)
+    .attr("fill", d => colourScale(d.depth))
+    .attr("stroke", "white")
+    .attr("stroke-width", 1);
+    
+}, [data]);
+```
+
+### Chord diagram
+
+```javascript
+function drawChordDiagram(data) {
+  // data format: array of objects with source, target, and value
+  // Example: [{ source: 'A', target: 'B', value: 10 }, ...]
+
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart');
+  svg.selectAll("*").remove();
+
+  const width = 600;
+  const height = 600;
+  const innerRadius = Math.min(width, height) * 0.3;
+  const outerRadius = innerRadius + 30;
+
+  // Create matrix from data
+  const nodes = Array.from(new Set(data.flatMap(d => [d.source, d.target])));
+  const matrix = Array.from({ length: nodes.length }, () => Array(nodes.length).fill(0));
+
+  data.forEach(d => {
+    const i = nodes.indexOf(d.source);
+    const j = nodes.indexOf(d.target);
+    matrix[i][j] += d.value;
+    matrix[j][i] += d.value;
+  });
+
+  // Create chord layout
+  const chord = d3.chord()
+    .padAngle(0.05)
+    .sortSubgroups(d3.descending);
+
+  const arc = d3.arc()
+    .innerRadius(innerRadius)
+    .outerRadius(outerRadius);
+
+  const ribbon = d3.ribbon()
+    .source(d => d.source)
+    .target(d => d.target);
+
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10)
+    .domain(nodes);
+
+  const g = svg.append("g")
+    .attr("transform", `translate(${width / 2},${height / 2})`);
+
+  const chords = chord(matrix);
+
+  // Draw ribbons
+  g.append("g")
+    .attr("fill-opacity", 0.67)
+    .selectAll("path")
+    .data(chords)
+    .join("path")
+    .attr("d", ribbon)
+    .attr("fill", d => colourScale(nodes[d.source.index]))
+    .attr("stroke", d => d3.rgb(colourScale(nodes[d.source.index])).darker());
+
+  // Draw groups (arcs)
+  const group = g.append("g")
+    .selectAll("g")
+    .data(chords.groups)
+    .join("g");
+
+  group.append("path")
+    .attr("d", arc)
+    .attr("fill", d => colourScale(nodes[d.index]))
+    .attr("stroke", d => d3.rgb(colourScale(nodes[d.index])).darker());
+
+  // Add labels
+  group.append("text")
+    .each(d => { d.angle = (d.startAngle + d.endAngle) / 2; })
+    .attr("dy", "0.31em")
+    .attr("transform", d => `rotate(${(d.angle * 180 / Math.PI) - 90})translate(${outerRadius + 30})${d.angle > Math.PI ? "rotate(180)" : ""}`)
+    .attr("text-anchor", d => d.angle > Math.PI ? "end" : null)
+    .text((d, i) => nodes[i])
+    .style("font-size", "12px");
+}
+
+// Data format example:
+// const data = [
+//   { source: 'Category A', target: 'Category B', value: 100 },
+//   { source: 'Category A', target: 'Category C', value: 50 },
+//   { source: 'Category B', target: 'Category C', value: 75 }
+// ];
+// drawChordDiagram(data);
+```
+
+## Advanced chart types
+
+### Heatmap
+
+```javascript
+function drawHeatmap(data) {
+  // data format: array of objects with row, column, and value
+  // Example: [{ row: 'A', column: 'X', value: 10 }, ...]
+
+  if (!data || data.length === 0) return;
+
+  const svg = d3.select('#chart');
+  svg.selectAll("*").remove();
+
+  const width = 800;
+  const height = 600;
+  const margin = { top: 100, right: 30, bottom: 30, left: 100 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+
+  // Get unique rows and columns
+  const rows = Array.from(new Set(data.map(d => d.row)));
+  const columns = Array.from(new Set(data.map(d => d.column)));
+
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+
+  // Create scales
+  const xScale = d3.scaleBand()
+    .domain(columns)
+    .range([0, innerWidth])
+    .padding(0.01);
+
+  const yScale = d3.scaleBand()
+    .domain(rows)
+    .range([0, innerHeight])
+    .padding(0.01);
+
+  // Colour scale for values (sequential from light to dark red)
+  const colourScale = d3.scaleSequential(d3.interpolateYlOrRd)
+    .domain([0, d3.max(data, d => d.value)]);
+
+  // Draw rectangles
+  g.selectAll("rect")
+    .data(data)
+    .join("rect")
+    .attr("x", d => xScale(d.column))
+    .attr("y", d => yScale(d.row))
+    .attr("width", xScale.bandwidth())
+    .attr("height", yScale.bandwidth())
+    .attr("fill", d => colourScale(d.value));
+
+  // Add x-axis labels
+  svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`)
+    .selectAll("text")
+    .data(columns)
+    .join("text")
+    .attr("x", d => xScale(d) + xScale.bandwidth() / 2)
+    .attr("y", -10)
+    .attr("text-anchor", "middle")
+    .text(d => d)
+    .style("font-size", "12px");
+
+  // Add y-axis labels
+  svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`)
+    .selectAll("text")
+    .data(rows)
+    .join("text")
+    .attr("x", -10)
+    .attr("y", d => yScale(d) + yScale.bandwidth() / 2)
+    .attr("dy", "0.35em")
+    .attr("text-anchor", "end")
+    .text(d => d)
+    .style("font-size", "12px");
+
+  // Add colour legend
+  const legendWidth = 20;
+  const legendHeight = 200;
+  const legend = svg.append("g")
+    .attr("transform", `translate(${width - 60},${margin.top})`);
+
+  const legendScale = d3.scaleLinear()
+    .domain(colourScale.domain())
+    .range([legendHeight, 0]);
+
+  const legendAxis = d3.axisRight(legendScale).ticks(5);
+
+  // Draw colour gradient in legend
+  for (let i = 0; i < legendHeight; i++) {
+    legend.append("rect")
+      .attr("y", i)
+      .attr("width", legendWidth)
+      .attr("height", 1)
+      .attr("fill", colourScale(legendScale.invert(i)));
+  }
+
+  legend.append("g")
+    .attr("transform", `translate(${legendWidth},0)`)
+    .call(legendAxis);
+}
+
+// Data format example:
+// const data = [
+//   { row: 'Monday', column: 'Morning', value: 42 },
+//   { row: 'Monday', column: 'Afternoon', value: 78 },
+//   { row: 'Tuesday', column: 'Morning', value: 65 },
+//   { row: 'Tuesday', column: 'Afternoon', value: 55 }
+// ];
+// drawHeatmap(data);
+```
+
+### Area chart with gradient
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+  
+  // Define gradient
+  const defs = svg.append("defs");
+  const gradient = defs.append("linearGradient")
+    .attr("id", "areaGradient")
+    .attr("x1", "0%")
+    .attr("x2", "0%")
+    .attr("y1", "0%")
+    .attr("y2", "100%");
+  
+  gradient.append("stop")
+    .attr("offset", "0%")
+    .attr("stop-color", "steelblue")
+    .attr("stop-opacity", 0.8);
+  
+  gradient.append("stop")
+    .attr("offset", "100%")
+    .attr("stop-color", "steelblue")
+    .attr("stop-opacity", 0.1);
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+  
+  const xScale = d3.scaleTime()
+    .domain(d3.extent(data, d => d.date))
+    .range([0, innerWidth]);
+  
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.value)])
+    .range([innerHeight, 0]);
+  
+  const area = d3.area()
+    .x(d => xScale(d.date))
+    .y0(innerHeight)
+    .y1(d => yScale(d.value))
+    .curve(d3.curveMonotoneX);
+  
+  g.append("path")
+    .datum(data)
+    .attr("fill", "url(#areaGradient)")
+    .attr("d", area);
+  
+  const line = d3.line()
+    .x(d => xScale(d.date))
+    .y(d => yScale(d.value))
+    .curve(d3.curveMonotoneX);
+  
+  g.append("path")
+    .datum(data)
+    .attr("fill", "none")
+    .attr("stroke", "steelblue")
+    .attr("stroke-width", 2)
+    .attr("d", line);
+  
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(d3.axisBottom(xScale));
+  
+  g.append("g")
+    .call(d3.axisLeft(yScale));
+    
+}, [data]);
+```
+
+### Stacked bar chart
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+  
+  const categories = Object.keys(data[0]).filter(k => k !== 'group');
+  const stackedData = d3.stack().keys(categories)(data);
+  
+  const xScale = d3.scaleBand()
+    .domain(data.map(d => d.group))
+    .range([0, innerWidth])
+    .padding(0.1);
+  
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(stackedData[stackedData.length - 1], d => d[1])])
+    .range([innerHeight, 0]);
+  
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+  
+  g.selectAll("g")
+    .data(stackedData)
+    .join("g")
+    .attr("fill", (d, i) => colourScale(i))
+    .selectAll("rect")
+    .data(d => d)
+    .join("rect")
+    .attr("x", d => xScale(d.data.group))
+    .attr("y", d => yScale(d[1]))
+    .attr("height", d => yScale(d[0]) - yScale(d[1]))
+    .attr("width", xScale.bandwidth());
+  
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(d3.axisBottom(xScale));
+  
+  g.append("g")
+    .call(d3.axisLeft(yScale));
+    
+}, [data]);
+```
+
+### Grouped bar chart
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+  
+  const categories = Object.keys(data[0]).filter(k => k !== 'group');
+  
+  const x0Scale = d3.scaleBand()
+    .domain(data.map(d => d.group))
+    .range([0, innerWidth])
+    .padding(0.1);
+  
+  const x1Scale = d3.scaleBand()
+    .domain(categories)
+    .range([0, x0Scale.bandwidth()])
+    .padding(0.05);
+  
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => Math.max(...categories.map(c => d[c])))])
+    .range([innerHeight, 0]);
+  
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+  
+  const group = g.selectAll("g")
+    .data(data)
+    .join("g")
+    .attr("transform", d => `translate(${x0Scale(d.group)},0)`);
+  
+  group.selectAll("rect")
+    .data(d => categories.map(key => ({ key, value: d[key] })))
+    .join("rect")
+    .attr("x", d => x1Scale(d.key))
+    .attr("y", d => yScale(d.value))
+    .attr("width", x1Scale.bandwidth())
+    .attr("height", d => innerHeight - yScale(d.value))
+    .attr("fill", d => colourScale(d.key));
+  
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(d3.axisBottom(x0Scale));
+  
+  g.append("g")
+    .call(d3.axisLeft(yScale));
+    
+}, [data]);
+```
+
+### Bubble chart
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 600;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+  
+  const xScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.x)])
+    .range([0, innerWidth]);
+  
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.y)])
+    .range([innerHeight, 0]);
+  
+  const sizeScale = d3.scaleSqrt()
+    .domain([0, d3.max(data, d => d.size)])
+    .range([0, 50]);
+  
+  const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+  
+  g.selectAll("circle")
+    .data(data)
+    .join("circle")
+    .attr("cx", d => xScale(d.x))
+    .attr("cy", d => yScale(d.y))
+    .attr("r", d => sizeScale(d.size))
+    .attr("fill", d => colourScale(d.category))
+    .attr("opacity", 0.6)
+    .attr("stroke", "white")
+    .attr("stroke-width", 2);
+  
+  g.append("g")
+    .attr("transform", `translate(0,${innerHeight})`)
+    .call(d3.axisBottom(xScale));
+  
+  g.append("g")
+    .call(d3.axisLeft(yScale));
+    
+}, [data]);
+```
+
+## Geographic visualisations
+
+### Basic map with points
+
+```javascript
+useEffect(() => {
+  if (!geoData || !pointData) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 600;
+  
+  const projection = d3.geoMercator()
+    .fitSize([width, height], geoData);
+  
+  const pathGenerator = d3.geoPath().projection(projection);
+  
+  // Draw map
+  svg.selectAll("path")
+    .data(geoData.features)
+    .join("path")
+    .attr("d", pathGenerator)
+    .attr("fill", "#e0e0e0")
+    .attr("stroke", "#999")
+    .attr("stroke-width", 0.5);
+  
+  // Draw points
+  svg.selectAll("circle")
+    .data(pointData)
+    .join("circle")
+    .attr("cx", d => projection([d.longitude, d.latitude])[0])
+    .attr("cy", d => projection([d.longitude, d.latitude])[1])
+    .attr("r", 5)
+    .attr("fill", "steelblue")
+    .attr("opacity", 0.7);
+    
+}, [geoData, pointData]);
+```
+
+### Choropleth map
+
+```javascript
+useEffect(() => {
+  if (!geoData || !valueData) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 600;
+  
+  const projection = d3.geoMercator()
+    .fitSize([width, height], geoData);
+  
+  const pathGenerator = d3.geoPath().projection(projection);
+  
+  // Create value lookup
+  const valueLookup = new Map(valueData.map(d => [d.id, d.value]));
+  
+  // Colour scale
+  const colourScale = d3.scaleSequential(d3.interpolateBlues)
+    .domain([0, d3.max(valueData, d => d.value)]);
+  
+  svg.selectAll("path")
+    .data(geoData.features)
+    .join("path")
+    .attr("d", pathGenerator)
+    .attr("fill", d => {
+      const value = valueLookup.get(d.id);
+      return value ? colourScale(value) : "#e0e0e0";
+    })
+    .attr("stroke", "#999")
+    .attr("stroke-width", 0.5);
+    
+}, [geoData, valueData]);
+```
+
+## Advanced interactions
+
+### Brush and zoom
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  svg.selectAll("*").remove();
+  
+  const width = 800;
+  const height = 400;
+  const margin = { top: 20, right: 30, bottom: 40, left: 50 };
+  const innerWidth = width - margin.left - margin.right;
+  const innerHeight = height - margin.top - margin.bottom;
+  
+  const xScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.x)])
+    .range([0, innerWidth]);
+  
+  const yScale = d3.scaleLinear()
+    .domain([0, d3.max(data, d => d.y)])
+    .range([innerHeight, 0]);
+  
+  const g = svg.append("g")
+    .attr("transform", `translate(${margin.left},${margin.top})`);
+  
+  const circles = g.selectAll("circle")
+    .data(data)
+    .join("circle")
+    .attr("cx", d => xScale(d.x))
+    .attr("cy", d => yScale(d.y))
+    .attr("r", 5)
+    .attr("fill", "steelblue");
+  
+  // Add brush
+  const brush = d3.brush()
+    .extent([[0, 0], [innerWidth, innerHeight]])
+    .on("start brush", (event) => {
+      if (!event.selection) return;
+      
+      const [[x0, y0], [x1, y1]] = event.selection;
+      
+      circles.attr("fill", d => {
+        const cx = xScale(d.x);
+        const cy = yScale(d.y);
+        return (cx >= x0 && cx <= x1 && cy >= y0 && cy <= y1) 
+          ? "orange" 
+          : "steelblue";
+      });
+    });
+  
+  g.append("g")
+    .attr("class", "brush")
+    .call(brush);
+    
+}, [data]);
+```
+
+### Linked brushing between charts
+
+```javascript
+function LinkedCharts({ data }) {
+  const [selectedPoints, setSelectedPoints] = useState(new Set());
+  const svg1Ref = useRef();
+  const svg2Ref = useRef();
+  
+  useEffect(() => {
+    // Chart 1: Scatter plot
+    const svg1 = d3.select(svg1Ref.current);
+    svg1.selectAll("*").remove();
+    
+    // ... create first chart ...
+    
+    const circles1 = svg1.selectAll("circle")
+      .data(data)
+      .join("circle")
+      .attr("fill", d => selectedPoints.has(d.id) ? "orange" : "steelblue");
+    
+    // Chart 2: Bar chart
+    const svg2 = d3.select(svg2Ref.current);
+    svg2.selectAll("*").remove();
+    
+    // ... create second chart ...
+    
+    const bars = svg2.selectAll("rect")
+      .data(data)
+      .join("rect")
+      .attr("fill", d => selectedPoints.has(d.id) ? "orange" : "steelblue");
+    
+    // Add brush to first chart
+    const brush = d3.brush()
+      .on("start brush end", (event) => {
+        if (!event.selection) {
+          setSelectedPoints(new Set());
+          return;
+        }
+        
+        const [[x0, y0], [x1, y1]] = event.selection;
+        const selected = new Set();
+        
+        data.forEach(d => {
+          const x = xScale(d.x);
+          const y = yScale(d.y);
+          if (x >= x0 && x <= x1 && y >= y0 && y <= y1) {
+            selected.add(d.id);
+          }
+        });
+        
+        setSelectedPoints(selected);
+      });
+    
+    svg1.append("g").call(brush);
+    
+  }, [data, selectedPoints]);
+  
+  return (
+    <div>
+      <svg ref={svg1Ref} width="400" height="300" />
+      <svg ref={svg2Ref} width="400" height="300" />
+    </div>
+  );
+}
+```
+
+## Animation patterns
+
+### Enter, update, exit with transitions
+
+```javascript
+useEffect(() => {
+  if (!data || data.length === 0) return;
+  
+  const svg = d3.select(svgRef.current);
+  
+  const circles = svg.selectAll("circle")
+    .data(data, d => d.id); // Key function for object constancy
+  
+  // EXIT: Remove old elements
+  circles.exit()
+    .transition()
+    .duration(500)
+    .attr("r", 0)
+    .remove();
+  
+  // UPDATE: Modify existing elements
+  circles
+    .transition()
+    .duration(500)
+    .attr("cx", d => xScale(d.x))
+    .attr("cy", d => yScale(d.y))
+    .attr("fill", "steelblue");
+  
+  // ENTER: Add new elements
+  circles.enter()
+    .append("circle")
+    .attr("cx", d => xScale(d.x))
+    .attr("cy", d => yScale(d.y))
+    .attr("r", 0)
+    .attr("fill", "steelblue")
+    .transition()
+    .duration(500)
+    .attr("r", 5);
+    
+}, [data]);
+```
+
+### Path morphing
+
+```javascript
+useEffect(() => {
+  if (!data1 || !data2) return;
+  
+  const svg = d3.select(svgRef.current);
+  
+  const line = d3.line()
+    .x(d => xScale(d.x))
+    .y(d => yScale(d.y))
+    .curve(d3.curveMonotoneX);
+  
+  const path = svg.select("path");
+  
+  // Morph from data1 to data2
+  path
+    .datum(data1)
+    .attr("d", line)
+    .transition()
+    .duration(1000)
+    .attrTween("d", function() {
+      const previous = d3.select(this).attr("d");
+      const current = line(data2);
+      return d3.interpolatePath(previous, current);
+    });
+    
+}, [data1, data2]);
+```

.claude/skills/d3-viz/references/scale-reference.md

@@ -0,0 +1,509 @@
+# D3.js Scale Reference
+
+Comprehensive guide to all d3 scale types with examples and use cases.
+
+## Continuous scales
+
+### Linear scale
+
+Maps continuous input domain to continuous output range with linear interpolation.
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range([0, 500]);
+
+scale(50);  // Returns 250
+scale(0);   // Returns 0
+scale(100); // Returns 500
+
+// Invert scale (get input from output)
+scale.invert(250); // Returns 50
+```
+
+**Use cases:**
+- Most common scale for quantitative data
+- Axes, bar lengths, position encoding
+- Temperature, prices, counts, measurements
+
+**Methods:**
+- `.domain([min, max])` - Set input domain
+- `.range([min, max])` - Set output range
+- `.invert(value)` - Get domain value from range value
+- `.clamp(true)` - Restrict output to range bounds
+- `.nice()` - Extend domain to nice round values
+
+### Power scale
+
+Maps continuous input to continuous output with exponential transformation.
+
+```javascript
+const sqrtScale = d3.scalePow()
+  .exponent(0.5)  // Square root
+  .domain([0, 100])
+  .range([0, 500]);
+
+const squareScale = d3.scalePow()
+  .exponent(2)  // Square
+  .domain([0, 100])
+  .range([0, 500]);
+
+// Shorthand for square root
+const sqrtScale2 = d3.scaleSqrt()
+  .domain([0, 100])
+  .range([0, 500]);
+```
+
+**Use cases:**
+- Perceptual scaling (human perception is non-linear)
+- Area encoding (use square root to map values to circle radii)
+- Emphasising differences in small or large values
+
+### Logarithmic scale
+
+Maps continuous input to continuous output with logarithmic transformation.
+
+```javascript
+const logScale = d3.scaleLog()
+  .domain([1, 1000])  // Must be positive
+  .range([0, 500]);
+
+logScale(1);    // Returns 0
+logScale(10);   // Returns ~167
+logScale(100);  // Returns ~333
+logScale(1000); // Returns 500
+```
+
+**Use cases:**
+- Data spanning multiple orders of magnitude
+- Population, GDP, wealth distributions
+- Logarithmic axes
+- Exponential growth visualisations
+
+**Important:** Domain values must be strictly positive (>0).
+
+### Time scale
+
+Specialised linear scale for temporal data.
+
+```javascript
+const timeScale = d3.scaleTime()
+  .domain([new Date(2020, 0, 1), new Date(2024, 0, 1)])
+  .range([0, 800]);
+
+timeScale(new Date(2022, 0, 1)); // Returns 400
+
+// Invert to get date
+timeScale.invert(400); // Returns Date object for mid-2022
+```
+
+**Use cases:**
+- Time series visualisations
+- Timeline axes
+- Temporal animations
+- Date-based interactions
+
+**Methods:**
+- `.nice()` - Extend domain to nice time intervals
+- `.ticks(count)` - Generate nicely-spaced tick values
+- All linear scale methods apply
+
+### Quantize scale
+
+Maps continuous input to discrete output buckets.
+
+```javascript
+const quantizeScale = d3.scaleQuantize()
+  .domain([0, 100])
+  .range(['low', 'medium', 'high']);
+
+quantizeScale(25);  // Returns 'low'
+quantizeScale(50);  // Returns 'medium'
+quantizeScale(75);  // Returns 'high'
+
+// Get the threshold values
+quantizeScale.thresholds(); // Returns [33.33, 66.67]
+```
+
+**Use cases:**
+- Binning continuous data
+- Heat map colours
+- Risk categories (low/medium/high)
+- Age groups, income brackets
+
+### Quantile scale
+
+Maps continuous input to discrete output based on quantiles.
+
+```javascript
+const quantileScale = d3.scaleQuantile()
+  .domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20, 24]) // Sample data
+  .range(['low', 'medium', 'high']);
+
+quantileScale(8);  // Returns based on quantile position
+quantileScale.quantiles(); // Returns quantile thresholds
+```
+
+**Use cases:**
+- Equal-size groups regardless of distribution
+- Percentile-based categorisation
+- Handling skewed distributions
+
+### Threshold scale
+
+Maps continuous input to discrete output with custom thresholds.
+
+```javascript
+const thresholdScale = d3.scaleThreshold()
+  .domain([0, 10, 20])
+  .range(['freezing', 'cold', 'warm', 'hot']);
+
+thresholdScale(-5);  // Returns 'freezing'
+thresholdScale(5);   // Returns 'cold'
+thresholdScale(15);  // Returns 'warm'
+thresholdScale(25);  // Returns 'hot'
+```
+
+**Use cases:**
+- Custom breakpoints
+- Grade boundaries (A, B, C, D, F)
+- Temperature categories
+- Air quality indices
+
+## Sequential scales
+
+### Sequential colour scale
+
+Maps continuous input to continuous colour gradient.
+
+```javascript
+const colourScale = d3.scaleSequential(d3.interpolateBlues)
+  .domain([0, 100]);
+
+colourScale(0);   // Returns lightest blue
+colourScale(50);  // Returns mid blue
+colourScale(100); // Returns darkest blue
+```
+
+**Available interpolators:**
+
+**Single hue:**
+- `d3.interpolateBlues`, `d3.interpolateGreens`, `d3.interpolateReds`
+- `d3.interpolateOranges`, `d3.interpolatePurples`, `d3.interpolateGreys`
+
+**Multi-hue:**
+- `d3.interpolateViridis`, `d3.interpolateInferno`, `d3.interpolateMagma`
+- `d3.interpolatePlasma`, `d3.interpolateWarm`, `d3.interpolateCool`
+- `d3.interpolateCubehelixDefault`, `d3.interpolateTurbo`
+
+**Use cases:**
+- Heat maps, choropleth maps
+- Continuous data visualisation
+- Temperature, elevation, density
+
+### Diverging colour scale
+
+Maps continuous input to diverging colour gradient with a midpoint.
+
+```javascript
+const divergingScale = d3.scaleDiverging(d3.interpolateRdBu)
+  .domain([-10, 0, 10]);
+
+divergingScale(-10); // Returns red
+divergingScale(0);   // Returns white/neutral
+divergingScale(10);  // Returns blue
+```
+
+**Available interpolators:**
+- `d3.interpolateRdBu` - Red to blue
+- `d3.interpolateRdYlBu` - Red, yellow, blue
+- `d3.interpolateRdYlGn` - Red, yellow, green
+- `d3.interpolatePiYG` - Pink, yellow, green
+- `d3.interpolateBrBG` - Brown, blue-green
+- `d3.interpolatePRGn` - Purple, green
+- `d3.interpolatePuOr` - Purple, orange
+- `d3.interpolateRdGy` - Red, grey
+- `d3.interpolateSpectral` - Rainbow spectrum
+
+**Use cases:**
+- Data with meaningful midpoint (zero, average, neutral)
+- Positive/negative values
+- Above/below comparisons
+- Correlation matrices
+
+### Sequential quantile scale
+
+Combines sequential colour with quantile mapping.
+
+```javascript
+const sequentialQuantileScale = d3.scaleSequentialQuantile(d3.interpolateBlues)
+  .domain([3, 6, 7, 8, 8, 10, 13, 15, 16, 20, 24]);
+
+// Maps based on quantile position
+```
+
+**Use cases:**
+- Perceptually uniform binning
+- Handling outliers
+- Skewed distributions
+
+## Ordinal scales
+
+### Band scale
+
+Maps discrete input to continuous bands (rectangles) with optional padding.
+
+```javascript
+const bandScale = d3.scaleBand()
+  .domain(['A', 'B', 'C', 'D'])
+  .range([0, 400])
+  .padding(0.1);
+
+bandScale('A');           // Returns start position (e.g., 0)
+bandScale('B');           // Returns start position (e.g., 110)
+bandScale.bandwidth();    // Returns width of each band (e.g., 95)
+bandScale.step();         // Returns total step including padding
+bandScale.paddingInner(); // Returns inner padding (between bands)
+bandScale.paddingOuter(); // Returns outer padding (at edges)
+```
+
+**Use cases:**
+- Bar charts (most common use case)
+- Grouped elements
+- Categorical axes
+- Heat map cells
+
+**Padding options:**
+- `.padding(value)` - Sets both inner and outer padding (0-1)
+- `.paddingInner(value)` - Padding between bands (0-1)
+- `.paddingOuter(value)` - Padding at edges (0-1)
+- `.align(value)` - Alignment of bands (0-1, default 0.5)
+
+### Point scale
+
+Maps discrete input to continuous points (no width).
+
+```javascript
+const pointScale = d3.scalePoint()
+  .domain(['A', 'B', 'C', 'D'])
+  .range([0, 400])
+  .padding(0.5);
+
+pointScale('A'); // Returns position (e.g., 50)
+pointScale('B'); // Returns position (e.g., 150)
+pointScale('C'); // Returns position (e.g., 250)
+pointScale('D'); // Returns position (e.g., 350)
+pointScale.step(); // Returns distance between points
+```
+
+**Use cases:**
+- Line chart categorical x-axis
+- Scatter plot with categorical axis
+- Node positions in network graphs
+- Any point positioning for categories
+
+### Ordinal colour scale
+
+Maps discrete input to discrete output (colours, shapes, etc.).
+
+```javascript
+const colourScale = d3.scaleOrdinal(d3.schemeCategory10);
+
+colourScale('apples');  // Returns first colour
+colourScale('oranges'); // Returns second colour
+colourScale('apples');  // Returns same first colour (consistent)
+
+// Custom range
+const customScale = d3.scaleOrdinal()
+  .domain(['cat1', 'cat2', 'cat3'])
+  .range(['#FF6B6B', '#4ECDC4', '#45B7D1']);
+```
+
+**Built-in colour schemes:**
+
+**Categorical:**
+- `d3.schemeCategory10` - 10 colours
+- `d3.schemeAccent` - 8 colours
+- `d3.schemeDark2` - 8 colours
+- `d3.schemePaired` - 12 colours
+- `d3.schemePastel1` - 9 colours
+- `d3.schemePastel2` - 8 colours
+- `d3.schemeSet1` - 9 colours
+- `d3.schemeSet2` - 8 colours
+- `d3.schemeSet3` - 12 colours
+- `d3.schemeTableau10` - 10 colours
+
+**Use cases:**
+- Category colours
+- Legend items
+- Multi-series charts
+- Network node types
+
+## Scale utilities
+
+### Nice domain
+
+Extend domain to nice round values.
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0.201, 0.996])
+  .nice();
+
+scale.domain(); // Returns [0.2, 1.0]
+
+// With count (approximate tick count)
+const scale2 = d3.scaleLinear()
+  .domain([0.201, 0.996])
+  .nice(5);
+```
+
+### Clamping
+
+Restrict output to range bounds.
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range([0, 500])
+  .clamp(true);
+
+scale(-10); // Returns 0 (clamped)
+scale(150); // Returns 500 (clamped)
+```
+
+### Copy scales
+
+Create independent copies.
+
+```javascript
+const scale1 = d3.scaleLinear()
+  .domain([0, 100])
+  .range([0, 500]);
+
+const scale2 = scale1.copy();
+// scale2 is independent of scale1
+```
+
+### Tick generation
+
+Generate nice tick values for axes.
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range([0, 500]);
+
+scale.ticks(10);        // Generate ~10 ticks
+scale.tickFormat(10);   // Get format function for ticks
+scale.tickFormat(10, ".2f"); // Custom format (2 decimal places)
+
+// Time scale ticks
+const timeScale = d3.scaleTime()
+  .domain([new Date(2020, 0, 1), new Date(2024, 0, 1)]);
+
+timeScale.ticks(d3.timeYear);      // Yearly ticks
+timeScale.ticks(d3.timeMonth, 3);  // Every 3 months
+timeScale.tickFormat(5, "%Y-%m");  // Format as year-month
+```
+
+## Colour spaces and interpolation
+
+### RGB interpolation
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range(["blue", "red"]);
+// Default: RGB interpolation
+```
+
+### HSL interpolation
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range(["blue", "red"])
+  .interpolate(d3.interpolateHsl);
+// Smoother colour transitions
+```
+
+### Lab interpolation
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range(["blue", "red"])
+  .interpolate(d3.interpolateLab);
+// Perceptually uniform
+```
+
+### HCL interpolation
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 100])
+  .range(["blue", "red"])
+  .interpolate(d3.interpolateHcl);
+// Perceptually uniform with hue
+```
+
+## Common patterns
+
+### Diverging scale with custom midpoint
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([min, midpoint, max])
+  .range(["red", "white", "blue"])
+  .interpolate(d3.interpolateHcl);
+```
+
+### Multi-stop gradient scale
+
+```javascript
+const scale = d3.scaleLinear()
+  .domain([0, 25, 50, 75, 100])
+  .range(["#d53e4f", "#fc8d59", "#fee08b", "#e6f598", "#66c2a5"]);
+```
+
+### Radius scale for circles (perceptual)
+
+```javascript
+const radiusScale = d3.scaleSqrt()
+  .domain([0, d3.max(data, d => d.value)])
+  .range([0, 50]);
+
+// Use with circles
+circle.attr("r", d => radiusScale(d.value));
+```
+
+### Adaptive scale based on data range
+
+```javascript
+function createAdaptiveScale(data) {
+  const extent = d3.extent(data);
+  const range = extent[1] - extent[0];
+  
+  // Use log scale if data spans >2 orders of magnitude
+  if (extent[1] / extent[0] > 100) {
+    return d3.scaleLog()
+      .domain(extent)
+      .range([0, width]);
+  }
+  
+  // Otherwise use linear
+  return d3.scaleLinear()
+    .domain(extent)
+    .range([0, width]);
+}
+```
+
+### Colour scale with explicit categories
+
+```javascript
+const colourScale = d3.scaleOrdinal()
+  .domain(['Low Risk', 'Medium Risk', 'High Risk'])
+  .range(['#2ecc71', '#f39c12', '#e74c3c'])
+  .unknown('#95a5a6'); // Fallback for unknown values
+```

.ralph/loop.lock

@@ -0,0 +1,5 @@
+{
+  "pid": 864891,
+  "started": "2026-02-16T10:14:58.914587907Z",
+  "prompt": "[no prompt]"
+}

Ralph/archive/2026-02-16-constellation-overhaul/prd.json

@@ -0,0 +1,237 @@
+{
+  "project": "Portfolio — Career Constellation Clinical Pathway Overhaul",
+  "branchName": "ralph/constellation-overhaul",
+  "description": "Transform the CareerConstellation D3 force graph from a prototype-quality visualisation into a polished clinical patient pathway diagram — reversed timeline, dynamic height sync, refined node styling, bidirectional hover highlighting, and muted skill nodes that reveal on interaction.",
+  "userStories": [
+    {
+      "id": "US-001",
+      "title": "Reverse timeline direction to top = most recent",
+      "description": "As a visitor, I want the graph's vertical timeline to run top-to-bottom from 2025→2017 so it visually aligns with the reverse-chronological work experience cards in the adjacent column.",
+      "acceptanceCriteria": [
+        "yScale domain reversed: [maxYear, minYear] maps to [topPadding, height - bottomPadding] so 2025 is near the top and 2017 near the bottom",
+        "Role nodes appear at correct reversed year positions",
+        "Year labels along the timeline axis read top-to-bottom: 2025, 2024, ..., 2017",
+        "Skill nodes cluster around their linked roles at the correct vertical positions",
+        "Timeline vertical line, year dots, and horizontal guide lines all reflect the reversed scale",
+        "Screen reader description (srDescription) updated to mention reverse-chronological order",
+        "Typecheck passes (npm run typecheck)"
+      ],
+      "priority": 1,
+      "passes": true,
+      "notes": "In CareerConstellation.tsx, the yScale is defined at line ~153. Change .domain([minYear, maxYear]) to .domain([maxYear, minYear]). This reversal flows through all elements that use yScale. The buildScreenReaderDescription() function at line ~63 should also mention 'reverse-chronological order' in its output. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-002",
+      "title": "Dynamic height matching with work experience column",
+      "description": "As a visitor, I want the constellation graph to fill the same vertical space as the work experience column so both columns appear balanced.",
+      "acceptanceCriteria": [
+        "Remove fixed DESKTOP_HEIGHT, TABLET_HEIGHT, MOBILE_HEIGHT constants from CareerConstellation.tsx",
+        "CareerConstellation accepts an optional containerHeight prop (number) for the target height",
+        "DashboardLayout measures the rendered height of the .chronology-stream element using a ref and ResizeObserver",
+        "DashboardLayout passes the measured height (or a sensible fallback) to CareerConstellation as containerHeight",
+        "Graph container uses containerHeight when available, with a minimum of 400px",
+        "On mobile (single-column layout where .pathway-columns is 1fr), the graph uses a standalone fallback height of 360px",
+        "The viewBox and all D3 scales update correctly when height changes",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser: expand/collapse work experience cards and confirm graph height adjusts"
+      ],
+      "priority": 2,
+      "passes": true,
+      "notes": "Add a ref to the .chronology-stream div in DashboardLayout. Use ResizeObserver to measure its offsetHeight. Pass it as a prop to CareerConstellation. Inside the constellation, use this prop in the dimensions state instead of the fixed getHeight() function. The getHeight() function can become the fallback for when no containerHeight is provided. CSS class .pathway-graph-sticky already has position:sticky — the height change should work within that. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-003",
+      "title": "Clinical pathway background and timeline structure",
+      "description": "As a visitor, I want the graph to look like a clinical patient pathway diagram — clean, precise, and institutional — matching the GP system dashboard aesthetic.",
+      "acceptanceCriteria": [
+        "Background: remove the radial gradient, use a clean fill matching var(--surface) (#FFFFFF) or very subtle var(--bg-dashboard) (#F0F5F4)",
+        "Add a subtle 1px border to the SVG container via the wrapping div: border 1px solid var(--border-light), border-radius var(--radius-sm)",
+        "Timeline axis: refined 1px vertical rule using var(--border) colour (#D4E0DE), not the current thick teal line",
+        "Year markers: small horizontal ticks (6-8px wide) extending right from the timeline, not floating dots",
+        "Year labels: font-family var(--font-geist-mono), font-size 10px, fill var(--text-tertiary) (#8DA8A5)",
+        "Horizontal guide lines: very subtle — stroke-opacity 0.25, stroke-dasharray '3 4' (dotted), using var(--border-light)",
+        "Remove the existing legend box from inside the SVG entirely (replacement comes in US-008)",
+        "All colours use CSS custom property values from the design system",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — the graph background and structure should feel consistent with the rest of the dashboard tiles"
+      ],
+      "priority": 3,
+      "passes": true,
+      "notes": "Most changes are in the main useEffect that builds the SVG (starting around line 132). Remove the radialGradient defs and the rect that uses it. Replace with a simple rect fill. The legendGroup creation (lines ~221-265) should be removed entirely. The timeline vertical line (lines ~189-196) should change from stroke #A8C4BF / width 2 to the border token colour / width 1. Year dots (circle.year-dot) should become short horizontal ticks (line elements). Year guide lines should become dashed. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-004",
+      "title": "Role node redesign — clinical record pill badges",
+      "description": "As a visitor, I want role nodes to look like refined clinical record entries — rounded rectangle badges anchored to their timeline position.",
+      "acceptanceCriteria": [
+        "Role nodes rendered as rounded rectangles (pills): approximately 100px wide x 32px tall, with rx/ry 16px for pill shape",
+        "Each role node displays shortLabel text centred inside, using font-family var(--font-ui), weight 600, size 11px",
+        "Role node fill uses orgColor at 0.12 opacity, with a 1px border of orgColor at 0.4 opacity, and text in orgColor at full strength",
+        "A thin connector line (1px, var(--border) colour) links each role node horizontally back to the timeline axis at its year position",
+        "Role node hover state: border opacity increases to 0.7, shadow appears (approximate var(--shadow-sm))",
+        "Active/pinned role node: border becomes solid at full orgColor opacity, slightly stronger shadow",
+        "ROLE_RADIUS constant replaced with ROLE_WIDTH and ROLE_HEIGHT constants for the pill dimensions",
+        "Force simulation collision detection updated to use the pill dimensions (not circular radius)",
+        "Focus ring styling updated to surround the pill shape instead of the old circle",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — role nodes appear as labelled pill badges along the timeline"
+      ],
+      "priority": 4,
+      "passes": true,
+      "notes": "This changes role nodes from <circle> to <rect> with rounded corners. The nodeSelection code that filters d.type === 'role' (lines ~354-380) needs to append 'rect' instead of 'circle'. Position with x = -ROLE_WIDTH/2 and y = -ROLE_HEIGHT/2 so they centre on the force simulation position. The focus-ring can also become a rect. The text element stays largely the same but needs its positioning adjusted (no more dy offset needed if dominant-baseline is middle). The collision force for roles should use a radius roughly equal to Math.max(ROLE_WIDTH, ROLE_HEIGHT)/2 + padding. The connector line should go from the timeline X position to the left edge of the pill node. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-005",
+      "title": "Skill node redesign — muted default with reveal on interaction",
+      "description": "As a visitor, I want skill nodes to be visually subdued by default, becoming prominent only when a connected role or skill is hovered or clicked.",
+      "acceptanceCriteria": [
+        "Default (resting) state: small circles radius 7px, fill-opacity 0.2, no visible label (label opacity 0)",
+        "Skill node fill colours by domain: technical uses var(--accent) #0D6E6E, clinical uses var(--success) #059669, leadership uses var(--amber) #D97706",
+        "When a connected role is hovered/pinned: connected skill nodes transition to radius 11px, fill-opacity 0.85, labels fade in (opacity 0 → 1)",
+        "Skill labels: font-family var(--font-geist-mono), font-size 10px, fill var(--text-secondary) (#5B7A78)",
+        "When a skill node itself is hovered: that skill and all connected roles highlight, skill grows to full size with label visible",
+        "Link lines default state: opacity 0.08, colour var(--border-light) — barely visible",
+        "Link lines highlighted state: opacity 0.55, colour matching the skill's domain colour, stroke-width 1.5px",
+        "Unconnected nodes (not in the active highlight group) reduce to opacity 0.06 — nearly invisible",
+        "All transitions 150-200ms and respect prefers-reduced-motion (skip to final state)",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — graph looks clean and quiet at rest, informative on hover"
+      ],
+      "priority": 5,
+      "passes": true,
+      "notes": "This modifies the applyGraphHighlight() function (line ~439) and the initial skill node rendering (lines ~382-403). The resting state setup happens when nodes are first created and in the 'no activeNodeId' branch of applyGraphHighlight. The highlighted state logic is in the activeNodeId branch. Key change: skill labels default to opacity 0 (not the current collision-based visibility), and only become visible via applyGraphHighlight when connected. The updateSkillLabelVisibility() function can be simplified or merged into applyGraphHighlight. The SKILL_RADIUS constant should be split into SKILL_RADIUS_DEFAULT (7) and SKILL_RADIUS_ACTIVE (11). Link line styling in the resting branch should use much lower opacity than current 0.45. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-006",
+      "title": "Bidirectional hover — graph node highlights timeline card",
+      "description": "As a visitor, I want hovering a role node in the graph to highlight the corresponding work experience card in the timeline, creating a clear bidirectional link.",
+      "acceptanceCriteria": [
+        "CareerConstellation gains a new prop: onNodeHover?: (id: string | null) => void",
+        "Role node mouseenter fires onNodeHover(d.id), mouseleave fires onNodeHover(null)",
+        "DashboardLayout passes onNodeHover callback to CareerConstellation and stores result as highlightedRoleId state",
+        "WorkExperienceSubsection gains a new prop: highlightedRoleId?: string | null",
+        "When highlightedRoleId matches a RoleItem's consultation.id, that card shows a subtle highlight: border-color var(--accent-border), background rgba(10,128,128,0.03)",
+        "LastConsultationSubsection also gains highlightedRoleId prop and participates in the highlight system for the most recent role (consultations[0].id)",
+        "Highlight clears when mouse leaves both the card and graph node",
+        "On touch devices, tap-to-pin works: tapping a role pins the highlight in both graph and timeline",
+        "Existing onNodeHighlight (timeline → graph) continues to work alongside the new reverse direction",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — hover graph nodes and confirm timeline cards highlight; hover timeline cards and confirm graph highlights"
+      ],
+      "priority": 6,
+      "passes": true,
+      "notes": "This adds the reverse direction to the existing partial bidirectional system. Currently DashboardLayout has handleNodeHighlight which sets highlightedNodeId (timeline → graph). The new onNodeHover adds graph → timeline. Both pieces of state coexist. In WorkExperienceSubsection, add a style to the RoleItem wrapper div that applies when highlightedRoleId matches — a subtle border and background change. For LastConsultationSubsection, apply the same highlight logic to its outer wrapper. The touch/pin logic in CareerConstellation already handles pinnedNodeId — the new onNodeHover should also fire for pinned nodes so timeline cards stay highlighted."
+    },
+    {
+      "id": "US-007",
+      "title": "Curved link lines between roles and skills",
+      "description": "As a visitor, I want the connection lines between roles and skills to be smooth curves rather than basic straight lines, matching a clinical pathway aesthetic.",
+      "acceptanceCriteria": [
+        "Replace <line> elements with <path> elements for links",
+        "Use D3 curve generators (d3.curveBasis or d3.line().curve(d3.curveBasis)) to create smooth curves between source and target",
+        "Default link styling: 1px stroke, colour var(--border-light), opacity 0.08 — barely visible at rest",
+        "Highlighted link styling: 1.5px stroke, domain colour of the skill end, opacity proportional to link strength value (range 0.35-0.65)",
+        "The tick handler updates path d attributes instead of line x1/y1/x2/y2",
+        "Links animate smoothly between default and highlighted states (CSS transition on stroke, stroke-opacity, stroke-width)",
+        "Respect prefers-reduced-motion — skip transitions",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — links are nearly invisible at rest and clearly trace pathways on hover"
+      ],
+      "priority": 7,
+      "passes": true,
+      "notes": "The linkSelection is created at lines ~340-345. Change from .join('line') to .join('path'). For the curve, generate a simple quadratic or cubic bezier path string in the tick handler: given source (sx,sy) and target (tx,ty), create a path like M sx,sy Q cx,cy tx,ty where cx,cy is a control point offset to create a gentle arc. A simple approach: control point at ((sx+tx)/2, sy) or ((sx+tx)/2, (sy+ty)/2 + offset). Alternatively use d3.linkHorizontal() or d3.linkVertical() which generate smooth curves between two points. The applyGraphHighlight function's link styling (lines ~465-482) needs updating from line attributes to path attributes — but stroke/stroke-opacity/stroke-width work the same on paths. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-008",
+      "title": "Compact domain legend as HTML below SVG",
+      "description": "As a visitor, I want a small unobtrusive legend explaining the domain colour coding, rendered as HTML below the graph.",
+      "acceptanceCriteria": [
+        "A compact single-line legend rendered as a React div below the SVG element, inside the CareerConstellation container",
+        "Legend shows three small coloured dots (6px circles) with labels: 'Technical', 'Clinical', 'Leadership' using the domain colours (var(--accent), var(--success), var(--amber))",
+        "Legend text: font-family var(--font-geist-mono), font-size 10px, colour var(--text-tertiary)",
+        "Items separated by subtle dot or pipe separators",
+        "Include hint text: 'Hover to explore connections' — same style, slightly more muted",
+        "Legend takes minimal vertical space (~24px total height)",
+        "Legend wraps gracefully on narrow screens (flex-wrap)",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser"
+      ],
+      "priority": 8,
+      "passes": true,
+      "notes": "This is pure React JSX added to the return block of CareerConstellation (after the SVG and before the closing container div). No D3 involved. Use inline styles consistent with the rest of the component, or simple Tailwind classes. The legend replaces the SVG-based legend that was removed in US-003. Position it as a flex row with gap: 12px, items centred vertically, padding: 6px 12px."
+    },
+    {
+      "id": "US-009",
+      "title": "Force simulation tuning for clinical layout",
+      "description": "As a developer, I want the D3 force simulation tuned so role nodes stay firmly anchored to timeline positions while skill nodes distribute cleanly to the right.",
+      "acceptanceCriteria": [
+        "Role nodes have very high forceY strength (0.95-1.0) and consistent forceX strength anchoring them at a fixed horizontal offset from the timeline",
+        "Skill nodes distribute in the space to the right of the role column, clustered near connected roles",
+        "Increase collision radius to prevent label overlap when skills are revealed on hover (account for SKILL_RADIUS_ACTIVE + label height)",
+        "Simulation alphaDecay tuned so graph stabilises within 1-2 seconds (or immediately for prefers-reduced-motion)",
+        "Boundary clamping keeps all nodes within the SVG viewport with adequate padding — role pill labels don't clip, skill labels don't overflow",
+        "On height changes (from US-002), simulation re-initialises without jarring jumps — preserve approximate positions",
+        "The charge force strength balanced to avoid nodes clustering too tightly or spreading too far",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser — nodes appear organised and intentional, not randomly scattered"
+      ],
+      "priority": 9,
+      "passes": true,
+      "notes": "The simulation is configured at lines ~515-532. Key parameters to tune: forceX/forceY strengths for roles (increase to ~1.0), forceX/forceY for skills (keep at 0.15-0.25 for organic clustering), charge strength (currently -85, may need adjustment with new pill-shaped roles), collide radius (needs to account for pill width for roles, and active radius + label for skills), link distance (currently 56, may need increase with larger role nodes). The alphaDecay is currently 0.06 for animated mode — could increase to 0.08-0.1 for faster settling. For the reduced-motion path, the 220 ticks (line 580) may need adjustment. Use the d3-viz skill for implementation."
+    },
+    {
+      "id": "US-010",
+      "title": "Content audit — verify role data against CV source",
+      "description": "As the portfolio owner, I want all role titles, organisations, dates, and achievement bullets verified against the source CV documents.",
+      "acceptanceCriteria": [
+        "Cross-reference src/data/consultations.ts against References/CV_v4.md and References/Andy_Charlwood_CV_ATS_Optimised.pdf",
+        "All role titles match the CV exactly",
+        "All organisation names are consistent (e.g., 'NHS Norfolk & Waveney ICB' everywhere, 'Tesco PLC' not 'Tesco')",
+        "All date ranges are correct (start/end for each role matching CV)",
+        "Achievement bullets (examination arrays) are accurate — numbers, percentages, claims match CV source",
+        "constellation.ts role node data (labels, shortLabels, orgColors, years) is consistent with consultations.ts",
+        "Any discrepancies found are fixed",
+        "Intentional abbreviations (e.g., shortened bullet text) are documented in code comments only where truly necessary",
+        "Typecheck passes (npm run typecheck)"
+      ],
+      "priority": 10,
+      "passes": true,
+      "notes": "Read src/data/consultations.ts and compare field-by-field against References/CV_v4.md. The CV has 4 roles: Interim Head (May-Nov 2025), Deputy Head (Jul 2024-Present), High-Cost Drugs (May 2022-Jul 2024), Pharmacy Manager (Nov 2017-May 2022). Check that consultations.ts has the same number of entries with matching data. Also verify constellation.ts nodes match — particularly startYear/endYear values and organization names. Fix any mismatches in the data files."
+    },
+    {
+      "id": "US-011",
+      "title": "Accessibility — fix focusable buttons and tab order",
+      "description": "As a visitor using assistive technology, I want the constellation graph to be keyboard navigable with proper focus rings and screen reader support.",
+      "acceptanceCriteria": [
+        "Hidden accessibility buttons have pointerEvents: 'auto' (not 'none') so they are actually focusable and clickable",
+        "Tab order follows reverse-chronological sequence: role nodes from most recent to oldest, then skill nodes grouped by domain (technical → clinical → leadership)",
+        "Focus ring styling is visible: 2px solid var(--accent) with 2px offset, matching design system",
+        "aria-label on the SVG updated to mention 'clinical pathway' metaphor",
+        "All interactive states (hover highlight, pin) are achievable via keyboard (Enter/Space to activate)",
+        "prefers-reduced-motion is respected — all animations skip to final state",
+        "Typecheck passes (npm run typecheck)"
+      ],
+      "priority": 11,
+      "passes": true,
+      "notes": "The accessibility buttons are at lines ~661-705 in the JSX. The critical bug is pointerEvents: 'none' on line 688 — change to 'auto'. Also check the containing div at line 658 which also has pointerEvents: 'none' — the buttons inside should override with 'auto'. The constellationNodes.map ordering determines tab order — consider sorting the nodes array for this specific rendering (roles first sorted by startYear desc, then skills grouped by domain). The focus/blur handlers at lines 692-693 already exist and work with the D3 focus ring. The SVG aria-label at line 629 should be updated."
+    },
+    {
+      "id": "US-012",
+      "title": "Responsive behaviour — mobile and tablet fallback",
+      "description": "As a visitor on a smaller screen, I want the constellation graph to display appropriately when the columns stack vertically.",
+      "acceptanceCriteria": [
+        "On mobile/tablet (single-column .pathway-columns layout), the graph renders at a fixed height of 360-400px since no column to match",
+        "The graph simplifies on small screens: role pill labels may use shorter text, skill node default radius decreases slightly (6px)",
+        "Touch interactions work correctly: tap to pin a node, tap elsewhere to unpin",
+        "Graph content is not cropped or overflowing on narrow viewports (min-width handling via boundary clamping)",
+        "The HTML legend from US-008 wraps gracefully on narrow screens",
+        "Timeline axis position adjusts for narrower viewports (closer to left edge)",
+        "Typecheck passes (npm run typecheck)",
+        "Verify in browser at mobile viewport widths (375px, 430px)"
+      ],
+      "priority": 12,
+      "passes": true,
+      "notes": "The current getHeight() function handles mobile with MOBILE_HEIGHT = 310. After US-002, the containerHeight prop drives the height on desktop. On mobile, detect that containerHeight is not being passed (or is invalid) and fall back to a fixed 360px. The CSS media query in index.css (line ~403) switches .pathway-columns to two-column at a certain breakpoint — below that, the graph is in a single-column stacked layout. The timelineX calculation (line 151) should account for narrow widths — Math.max(80, ...) to keep it accessible. Use the d3-viz skill for implementation."
+    }
+  ]
+}

Ralph/archive/2026-02-16-constellation-overhaul/progress.txt

@@ -0,0 +1,227 @@
+# Progress Log — Career Constellation Clinical Pathway Overhaul
+# Branch: ralph/constellation-overhaul
+# Started: 2026-02-16
+
+## Codebase Patterns
+- CareerConstellation.tsx is a D3 force-directed graph rendered in an SVG with React overlay buttons for accessibility
+- D3 simulation uses forceSimulation with charge, link, x, y, and collide forces
+- Module-level window.matchMedia reads for prefersReducedMotion and supportsCoarsePointer
+- DashboardLayout manages constellation state: highlightedNodeId, pinnedNodeId via callbacks
+- Work experience data in src/data/consultations.ts, skills in src/data/skills.ts, constellation-specific data in src/data/constellation.ts
+- CSS layout: .pathway-columns is a grid that switches from 1fr (mobile) to minmax(0,1.15fr) minmax(0,1.5fr) at desktop breakpoint
+- .pathway-graph-sticky has position: sticky; top: 12px; min-height: 100% for the graph column
+- containerHeight prop drives graph height on desktop; on mobile (viewport < 1024px) uses MOBILE_FALLBACK_HEIGHT (360px)
+- Use window.innerWidth for breakpoint checks, not container.clientWidth — the SVG container overflows on mobile
+- Design tokens in index.css :root — use var(--accent), var(--border-light), var(--text-tertiary), etc.
+- Use the d3-viz skill for all D3 rendering stories
+- yScale domain reversal automatically flows through all timeline elements (guides, dots, labels, role positions, simulation forces) — no per-element changes needed
+- Always use CSS custom properties (var(--border), var(--surface), var(--text-tertiary), etc.) for colours in D3 — never hardcode hex values
+- SVG shadows: use <filter> with <feDropShadow> in <defs>, apply to <g> groups via .attr('filter', 'url(#filter-id)'), clear with .attr('filter', null)
+- Role nodes are already pill-shaped rects (ROLE_WIDTH=104, ROLE_HEIGHT=32, ROLE_RX=16) with orgColor badge styling — check before re-implementing
+
+## 2026-02-16 - US-001
+- Reversed yScale domain from [minYear, maxYear] to [maxYear, minYear] so 2025 appears at top
+- Updated buildScreenReaderDescription() to mention reverse-chronological order
+- Files changed: src/components/CareerConstellation.tsx
+- **Learnings for future iterations:**
+  - The yScale is the single source of truth for vertical positioning — reversing its domain is a one-line change that cascades to all D3 elements using it
+  - Year guide lines, year dots, year labels, role initial positions, and simulation forceY all reference yScale — no individual element updates needed
+  - buildScreenReaderDescription() is defined at module level (line ~63), not inside the component
+---
+
+## 2026-02-16 - US-002
+- Removed fixed DESKTOP_HEIGHT/TABLET_HEIGHT/MOBILE_HEIGHT constants, replaced with MIN_HEIGHT (400) and MOBILE_FALLBACK_HEIGHT (360)
+- Added containerHeight prop to CareerConstellation — DashboardLayout measures .chronology-stream via ResizeObserver and passes height
+- getHeight() now takes containerHeight param: on mobile uses fallback, on desktop uses measured height with MIN_HEIGHT floor
+- Used window.innerWidth for mobile breakpoint detection (container.clientWidth is unreliable due to SVG overflow)
+- Files changed: src/components/CareerConstellation.tsx, src/components/DashboardLayout.tsx, src/index.css
+- **Learnings for future iterations:**
+  - The CareerConstellation container div overflows on mobile — its clientWidth reports desktop-sized values even at 375px viewport. Always use window.innerWidth for responsive breakpoint checks in this component.
+  - ResizeObserver on .chronology-stream fires when cards expand/collapse, triggering height update in the graph — this is the key mechanism for dynamic sync.
+  - The dimensions useEffect depends on [containerHeight] so it re-runs when the measured height changes, updating the D3 scales.
+  - CSS grid column ratio was adjusted to minmax(0,1.15fr) minmax(0,1.5fr) to give the graph more horizontal space.
+---
+
+## 2026-02-16 - US-003
+- Removed radial gradient background, replaced with clean var(--surface) fill
+- Added 1px solid var(--border-light) border to the container div
+- Refined timeline vertical rule to 1px stroke using var(--border) colour
+- Replaced year dots (circles) with horizontal tick marks (6-8px lines extending right from timeline)
+- Updated year labels fill to var(--text-tertiary)
+- Made horizontal guide lines subtle: stroke-opacity 0.25, stroke-dasharray '3 4', using var(--border-light)
+- Removed the entire SVG legend group (replacement HTML legend comes in US-008)
+- Files changed: src/components/CareerConstellation.tsx
+- **Learnings for future iterations:**
+  - All colours should use CSS custom property values (var(--border), var(--surface), etc.) rather than hardcoded hex values — the design system tokens are defined in index.css :root
+  - The legend was ~47 lines of D3 code; removing it is a significant net reduction. The HTML replacement in US-008 will be simpler React JSX
+  - Year ticks as horizontal lines are positioned with x1=timelineX, x2=timelineX+width — they extend right from the timeline axis, not centred on it
+  - The container div border + borderRadius + overflow:hidden creates a clean framed look for the SVG without needing an SVG-level border
+---
+
+## 2026-02-16 - US-004
+- Added SVG filter defs for drop shadows: shadow-sm-filter (subtle, for hover/connected) and shadow-md-filter (stronger, for active/pinned)
+- Updated applyGraphHighlight to apply shadow filters on role node `<g>` elements during highlight states
+- Resting state: no filter; connected role: shadow-sm; active/pinned role: shadow-md with stroke-opacity 1 and stroke-width 1.5
+- Note: most of US-004 (pill shape, orgColor styling, connector lines, focus rings, collision detection) was already implemented in prior iterations
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json
+- **Learnings for future iterations:**
+  - SVG drop shadows use `<filter>` with `<feDropShadow>` — apply to the parent `<g>` group, not the individual shape, for proper rendering
+  - Filter bounds need generous overflow (x/y -20%, width/height 140%+) to avoid clipping the shadow
+  - When clearing a filter, use `.attr('filter', null)` — not empty string
+  - The role node pill rendering (rect with rx/ry, orgColor fill at 0.12, border at 0.4) was built incrementally across US-003 and US-004 — check existing code before implementing to avoid duplication
+- Skill nodes use SKILL_RADIUS_DEFAULT (7) for resting state and SKILL_RADIUS_ACTIVE (11) for highlighted state — controlled via applyGraphHighlight, not CSS transitions (SVG `r` doesn't transition via CSS)
+- Skill labels default to opacity 0 and are shown/hidden via D3 transitions in applyGraphHighlight — the old updateSkillLabelVisibility collision-based approach was removed
+- Link lines use var(--border-light) at opacity 0.08 for resting state — highlighted links use the skill's domain colour from domainColorMap with strength-proportional opacity
+- Bidirectional highlighting uses two independent state vars in DashboardLayout: highlightedNodeId (timeline→graph) and highlightedRoleId (graph→timeline)
+- callbacksRef pattern in CareerConstellation prevents stale closures — always add new callbacks there
+- LastConsultationSubsection is defined inline in DashboardLayout.tsx, not a separate file
+- Link lines are `<path>` elements (not `<line>`) using quadratic bezier curves — tick handler sets `d` attr, not x1/y1/x2/y2. CSS transitions handle highlight animations on stroke properties
+- Accessibility buttons are overlaid React `<button>` elements at opacity 0 — container div has pointerEvents 'none', buttons have 'auto'. Tab order is controlled by DOM order (sort the array before .map())
+- Focus on an accessibility button should call `highlightGraphRef.current?.(node.id)` to trigger the D3 focus ring and graph highlights — otherwise keyboard users can't see which node they've tabbed to
+- Force simulation parameters: role forceX/Y strength ~1.0, skill forceX/Y ~0.18, charge -120 (role) / -55 (skill), link distance 72, collide iterations 2
+- Role homeX uses consistent offset (`timelineX + 80 + ROLE_WIDTH/2`), no jitter — roles align vertically
+- Skill homeX pushed right of roles: `skillSpaceStart = roleX + ROLE_WIDTH/2 + 40` ensures skills cluster in the right-side space
+- Boundary clamping accounts for `topPadding`/`bottomPadding` and `skillBottomPadding` (radius + gap + label line height) to prevent label clipping
+---
+
+## 2026-02-16 - US-005
+- Replaced SKILL_RADIUS (14) with SKILL_RADIUS_DEFAULT (7) and SKILL_RADIUS_ACTIVE (11)
+- Skill nodes now default to small (r=7), low opacity (0.2), no stroke, hidden labels (opacity 0)
+- On hover/pin: connected skills grow to r=11, fill-opacity 0.85, labels fade in; unconnected nodes dim to opacity 0.06
+- Link lines default to var(--border-light) at opacity 0.08; highlighted links use domain colour with strength-proportional opacity (0.35-0.65)
+- Removed updateSkillLabelVisibility function — label visibility now fully controlled by applyGraphHighlight
+- D3 transitions (180ms) used for skill radius and opacity changes, respecting prefers-reduced-motion
+- Updated collision force and boundary clamping to use SKILL_RADIUS_ACTIVE
+- Skill labels styled: font-geist-mono, 10px, var(--text-secondary)
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json
+- **Learnings for future iterations:**
+  - SVG `r` attribute cannot be animated via CSS transitions — must use D3 `.transition().duration()` for radius changes
+  - The applyGraphHighlight function is the single source of truth for all visual states (resting, highlighted, dimmed) — keep all styling logic there, not split between initial rendering and highlight
+  - D3 transition on a selection that already has a pending transition interrupts it — this is fine for hover interactions where the latest state wins
+  - domainColorMap hex values are needed for D3 attrs (can't use CSS custom properties for computed color values in stroke/fill of highlighted links)
+---
+
+## 2026-02-16 - US-006
+- Added `onNodeHover?: (id: string | null) => void` prop to CareerConstellation — fires on role node mouseenter/mouseleave and pin/unpin
+- Added `highlightedRoleId` state in DashboardLayout, wired via `handleNodeHover` callback
+- WorkExperienceSubsection receives `highlightedRoleId` prop; RoleItem shows subtle teal border + background tint when matched
+- LastConsultationSubsection receives `highlightedRoleId` prop; outer wrapper shows border/background highlight for consultations[0]
+- Existing timeline→graph direction (`onNodeHighlight` / `highlightedNodeId`) continues working alongside new reverse direction
+- Touch/pin: clicking/tapping a role node fires `onNodeHover` with the pinned role ID, keeping timeline card highlighted while pinned
+- Files changed: src/components/CareerConstellation.tsx, src/components/DashboardLayout.tsx, src/components/WorkExperienceSubsection.tsx
+- **Learnings for future iterations:**
+  - The bidirectional system uses two separate state variables: `highlightedNodeId` (timeline→graph) and `highlightedRoleId` (graph→timeline) — they coexist independently in DashboardLayout
+  - `callbacksRef` pattern in CareerConstellation avoids stale closure issues — add new callbacks there (e.g., `onNodeHover`) alongside existing ones
+  - For highlight styling on timeline cards, use `border: 1px solid transparent` as default with padding/margin compensation to prevent layout shift when highlighting activates
+  - LastConsultationSubsection is defined inline in DashboardLayout.tsx, not as a separate file — props must be threaded through the local function definition
+  - D3 mouseenter events on SVG `<g>` elements require direct mouse interaction with the SVG, not the React button overlay layer
+---
+
+## 2026-02-16 - US-007
+- Replaced straight `<line>` elements with curved `<path>` elements for link lines between roles and skills
+- Link paths use quadratic bezier curves: `M sx,sy Q cx,sy tx,ty` where cx is the horizontal midpoint — creating a gentle arc that exits horizontally from the role node before curving to the skill
+- Added `fill: none` to paths (required since paths auto-fill unlike lines)
+- Added CSS transitions on stroke/stroke-opacity/stroke-width (150ms ease) for smooth highlight animations, respecting prefers-reduced-motion
+- applyGraphHighlight link styling unchanged — stroke/stroke-opacity/stroke-width attributes work identically on `<path>` as on `<line>`
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json
+- **Learnings for future iterations:**
+  - When converting `<line>` to `<path>`, always add `fill: none` — SVG paths default to `fill: black` which would cover the curve area
+  - Quadratic bezier with control point at `((sx+tx)/2, sy)` creates a nice horizontal-exit curve from role nodes — the path leaves horizontally then arcs down/up to the skill
+  - CSS transitions work on SVG `<path>` stroke properties, so no D3 `.transition()` needed for link highlight animations (unlike `r` attribute which requires D3 transitions)
+  - The tick handler generates the `d` attribute string directly — simpler than using `d3.line().curve()` since we only need two-point curves
+---
+
+## 2026-02-16 - US-008
+- Added compact HTML legend below SVG inside CareerConstellation container
+- Legend shows three 6px coloured dots with labels: Technical (var(--accent)), Clinical (var(--success)), Leadership (var(--amber))
+- Items separated by middle dot (·) separators using var(--border) colour
+- Includes "Hover to explore connections" hint text at slightly reduced opacity (0.7)
+- Uses font-family var(--font-geist-mono), font-size 10px, colour var(--text-tertiary)
+- flex-wrap enabled for graceful narrowing on small screens
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json
+- **Learnings for future iterations:**
+  - The legend is pure React JSX — no D3 involved. Placed between the SVG and the screen reader description paragraph inside the container div
+  - Using React.Fragment with the `.map()` allows conditional separator rendering (skip before first item) without extra wrapper divs
+  - The container div's overflow:hidden clips the legend's border-radius corners cleanly
+---
+
+## 2026-02-16 - US-009
+- Tuned D3 force simulation for clinical layout — role nodes firmly anchored, skill nodes distributed cleanly to the right
+- Role positioning: removed jitter from homeX, all roles at consistent `timelineX + 80 + ROLE_WIDTH/2` offset
+- Skill positioning: pushed centroid right of roles (`skillSpaceStart = roleX + ROLE_WIDTH/2 + 40`) so skills cluster in available right-side space
+- Charge force: split by node type — roles get -120 (stronger repulsion for pill shapes), skills get -55 (moderate clustering)
+- Link distance increased from 56 to 72 to account for wider pill-shaped role nodes
+- Link strength reduced from `strength * 0.7` to `strength * 0.5` for more organic skill distribution
+- Skill forceX/Y strength reduced from 0.2 to 0.18 for slightly more organic spread
+- Role forceY reduced marginally from 1.0 to 0.98 (effectively still anchored but allows micro-adjustment)
+- Collision force: skill radius increased to `SKILL_RADIUS_ACTIVE + 16` (27px) to prevent label overlap on hover; added `.iterations(2)` for better separation
+- alphaDecay increased from 0.06 to 0.08 (animated) and 0.26 to 0.28 (reduced-motion) for faster settling (~1.5s)
+- Reduced-motion tick count decreased from 220 to 150 to match faster alphaDecay
+- Boundary clamping: roles now respect topPadding/bottomPadding; skills use skillBottomPadding (radius + gap + label height = 37px) and 40px right margin for label overflow
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json, Ralph/progress.txt
+- **Learnings for future iterations:**
+  - Split charge strength by node type (`d => d.type === 'role' ? -120 : -55`) — pill-shaped roles need stronger repulsion to avoid overlap while small skill nodes can cluster more tightly
+  - Collision `.iterations(2)` significantly improves separation quality for densely connected subgraphs at minimal performance cost
+  - Consistent role homeX (no jitter) creates a clean vertical column effect — visual order comes from the simulation, not random initial positioning
+  - Skill homeX centroid should be explicitly pushed right of the role column, not just inherited from role positions — the +60 offset plus skillSpaceStart ensures skills don't overlap role pills
+  - Boundary clamping must account for the full visual footprint including labels: for skills, that's radius + dy offset + text line height below the node center
+---
+
+## 2026-02-16 - US-010
+- Content audit: cross-referenced consultations.ts and constellation.ts against References/CV_v4.md
+- Verified all 4 role titles, organisation names, date ranges, and orgColor values match exactly
+- Verified all examination/achievement bullets (numbers, percentages, claims) are accurate against CV source
+- Verified constellation.ts role node labels, shortLabels, startYear/endYear, and organization names are consistent with consultations.ts
+- Verified plan arrays contain accurate outcomes matching CV content
+- No discrepancies found — no data file changes required
+- Note: `javascript-typescript` skill node in constellation.ts is an intentional orphan (no role links) — it's in the CV Core Competencies but not attributed to any specific role's achievements
+- Files changed: Ralph/prd.json (marked passes: true), Ralph/progress.txt
+- **Learnings for future iterations:**
+  - consultations.ts has 4 roles matching CV_v4.md exactly: Interim Head (May-Nov 2025), Deputy Head (Jul 2024-Present), High-Cost Drugs (May 2022-Jul 2024), Pharmacy Manager (Nov 2017-May 2022)
+  - constellation.ts role nodes use integer startYear/endYear (null for current roles) while consultations.ts uses formatted duration strings — both are consistent representations of the same dates
+  - The `javascript-typescript` skill node exists but has no constellationLinks entries — it appears in the graph as a disconnected node, which is intentional since JS/TS isn't attributed to any specific role
+  - codedEntries arrays in consultations.ts are portfolio-specific shorthand codes, not from the CV — they're part of the clinical metaphor design
+---
+
+## 2026-02-16 - US-011
+- Fixed accessibility button `pointerEvents` from `'none'` to `'auto'` so buttons are actually focusable and clickable
+- Sorted accessibility buttons for tab order: roles in reverse-chronological order (Interim Head → Deputy Head → HCD → Pharm Mgr), then skills grouped by domain (technical → clinical → leadership), alphabetically within each domain
+- Added focus ring for skill nodes (circle with radius SKILL_RADIUS_ACTIVE + 3) — previously only role nodes had focus rings
+- Updated focus ring stroke to use `var(--accent)` instead of hardcoded `#0D6E6E`
+- Updated SVG `aria-label` to mention "Clinical pathway constellation" and reverse-chronological order
+- Added keyboard focus triggers: when a button receives focus, the corresponding node highlights in the graph and fires `onNodeHover` for bidirectional highlighting
+- On blur, highlight reverts to pinned node state (or clears)
+- Verified prefers-reduced-motion is already properly respected throughout (no changes needed)
+- Files changed: src/components/CareerConstellation.tsx, Ralph/prd.json, Ralph/progress.txt
+- **Learnings for future iterations:**
+  - The accessibility buttons are React `<button>` elements overlaid on top of the SVG, positioned via `nodeButtonPositions` state — they are invisible (opacity: 0) but focusable
+  - The containing div has `pointerEvents: 'none'` correctly — only the buttons inside override with `pointerEvents: 'auto'`
+  - Tab order is determined by DOM order of the buttons, not by any `tabindex` — sorting the `constellationNodes` array before `.map()` controls the tab sequence
+  - Focus on a button should trigger `highlightGraphRef.current?.(node.id)` to show the D3 focus ring AND highlight connected nodes — without this, keyboard users can't see which node they've tabbed to
+  - The focus ring useEffect syncs `focusedNodeId` → D3 `.focus-ring` elements; it clears all first then applies to the focused one
+---
+
+## 2026-02-16 - US-012
+- Added mobile-responsive constants: MOBILE_ROLE_WIDTH (80), MOBILE_SKILL_RADIUS_DEFAULT (6), MOBILE_SKILL_RADIUS_ACTIVE (9)
+- Increased MOBILE_FALLBACK_HEIGHT from 360 to 380
+- Added `isMobile = window.innerWidth < 640` breakpoint detection in D3 effect (using window.innerWidth, not container.clientWidth, due to known overflow issue)
+- Computed responsive layout parameters: role width, skill radii, padding, timelineX, roleGap, skillGap all scale down on mobile
+- Mobile label truncation: roles 10 chars max, skills 12 chars max (with ellipsis)
+- Reduced force simulation parameters on mobile: charge -80/-35 (vs -120/-55), link distance 48 (vs 72), smaller collision radii
+- Fixed CSS grid overflow: added `min-width: 0` to `.pathway-columns` and `.pathway-graph-sticky`, plus `overflow: hidden` on `.pathway-graph-sticky`
+- Accessibility button width uses responsive check for mobile pill width
+- Verified at 375px (SVG 258x380), 430px (mobile layout), and 1440px (full desktop 1706px height)
+- Touch interactions (tap-to-pin) already worked via `supportsCoarsePointer` — no changes needed
+- HTML legend wraps gracefully on narrow screens via existing `flex-wrap`
+- Files changed: src/components/CareerConstellation.tsx, src/index.css, Ralph/prd.json, Ralph/progress.txt
+- **Learnings for future iterations:**
+  - CSS Grid children with `min-width: auto` (the default) allow oversized SVG content to overflow the grid cell. Fix with `min-width: 0` on the grid child and `overflow: hidden`
+  - Always use `window.innerWidth` for mobile breakpoint detection in CareerConstellation — `container.clientWidth` reports incorrect values due to the SVG overflow issue
+  - D3 force simulation parameters need separate tuning for mobile — smaller charge, shorter link distance, and tighter collision radii produce a compact layout that fits in ~260px width
+  - Label truncation prevents text overflow on mobile but loses information — keep truncation length generous enough to remain identifiable (10 chars for roles, 12 for skills)
+  - The `.pathway-graph-sticky` overflow fix must be `hidden` not `auto` to prevent scrollbars appearing inside the grid cell
+---
+
+## COMPLETE
+All 12 user stories (US-001 through US-012) implemented and passing.
+Feature branch: ralph/constellation-overhaul

Ralph/archive/2026-02-16-llm-cv-knowledge/prd.json

@@ -0,0 +1,376 @@
+{
+  "project": "Portfolio — LLM CV Knowledge Accuracy",
+  "branchName": "ralph/llm-cv-knowledge",
+  "description": "Migrate from Gemini to OpenRouter (z-ai/glm-5), enrich LLM context with full CV detail, and benchmark accuracy against 10 verifiable questions until 90%+ pass rate.",
+  "userStories": [
+    {
+      "id": "US-001",
+      "title": "Install @xenova/transformers and add generate-embeddings script skeleton",
+      "description": "As a developer, I need the Transformers.js dependency installed and a runnable script scaffold so subsequent stories can generate and use embeddings.",
+      "acceptanceCriteria": [
+        "npm install @xenova/transformers",
+        "Create scripts/generate-embeddings.ts with a main() function that imports the pipeline from @xenova/transformers",
+        "Script loads the all-MiniLM-L6-v2 model and embeds a single test string, logging the vector length to confirm it works",
+        "Add npm script: \"generate-embeddings\": \"npx tsx scripts/generate-embeddings.ts\"",
+        "Running npm run generate-embeddings prints the vector length (384) and exits cleanly",
+        "Typecheck passes"
+      ],
+      "priority": 1,
+      "passes": true,
+      "notes": "Use @xenova/transformers (not @huggingface/transformers — the Xenova fork has better Node.js ONNX support). The model ID is 'Xenova/all-MiniLM-L6-v2'. Pipeline type is 'feature-extraction'. tsx is already available via npx for running TypeScript scripts."
+    },
+    {
+      "id": "US-002",
+      "title": "Build rich text representations for each palette item",
+      "description": "As a developer, I want each palette item to have a natural-language paragraph for embedding that captures deep context, not just the title.",
+      "acceptanceCriteria": [
+        "New function buildEmbeddingTexts() in src/lib/search.ts that returns Array<{ id: string, text: string }> for all palette items",
+        "Consultation items include: role, org, duration, history narrative, examination bullets, coded entry descriptions",
+        "Skill items include: name, category, frequency, proficiency percentage, years of experience",
+        "KPI items include: value, label, explanation, story context and outcomes",
+        "Investigation items include: name, methodology, tech stack list, results",
+        "Education items include: title, institution, type, research detail",
+        "Quick Action items include: title and subtitle (short text is fine)",
+        "Achievement items include: title, subtitle, and linked KPI story context if available",
+        "Each text is a readable natural-language paragraph, not a keyword dump",
+        "Typecheck passes"
+      ],
+      "priority": 2,
+      "passes": true,
+      "notes": "This function will be used by both the build script (to generate embeddings) and potentially by the chat widget (for context). Import the raw data files (consultations, skills, kpis, investigations, documents) to access the full data beyond what buildPaletteData() surfaces. The id must match the PaletteItem id so embeddings can be correlated."
+    },
+    {
+      "id": "US-003",
+      "title": "Generate and commit embeddings.json",
+      "description": "As a developer, I want the generate-embeddings script to produce a complete embeddings.json file using the rich text representations.",
+      "acceptanceCriteria": [
+        "scripts/generate-embeddings.ts imports buildEmbeddingTexts() from src/lib/search.ts",
+        "Script embeds each item's text using the all-MiniLM-L6-v2 model via @xenova/transformers pipeline",
+        "Outputs src/data/embeddings.json as an array of { id: string, embedding: number[] }",
+        "Each embedding is a 384-dimensional float array",
+        "Running npm run generate-embeddings regenerates the file successfully",
+        "The JSON file is valid and parseable",
+        "Typecheck passes"
+      ],
+      "priority": 3,
+      "passes": true,
+      "notes": "The pipeline returns a Tensor — use .tolist() or .data to extract the raw float array. Mean-pool across the token dimension (dim 1) to get a single 384-d vector per input. Process items sequentially to avoid OOM in Node. The output file will be ~200KB for ~40 items with 384 floats each."
+    },
+    {
+      "id": "US-004",
+      "title": "Preload ONNX model during boot sequence",
+      "description": "As a visitor, I want the semantic search model to download in the background during the boot/ECG/login phases so it's ready when I reach the dashboard.",
+      "acceptanceCriteria": [
+        "New src/lib/embedding-model.ts module that exports: initModel(), embedQuery(text: string), and isModelReady()",
+        "initModel() loads the all-MiniLM-L6-v2 pipeline from @xenova/transformers and stores it in a module-level variable",
+        "embedQuery() returns a Promise<number[]> (384-d vector) for a given text string",
+        "isModelReady() returns boolean indicating if the model has finished loading",
+        "initModel() is called in App.tsx useEffect on mount (during boot phase) — fire and forget, no await",
+        "If initModel() fails (network error, etc.), isModelReady() remains false — no error thrown or shown",
+        "Model is cached by @xenova/transformers in IndexedDB — subsequent page loads are near-instant",
+        "Boot/ECG/login animations are not affected by model loading",
+        "Typecheck passes"
+      ],
+      "priority": 4,
+      "passes": true,
+      "notes": "Use pipeline('feature-extraction', 'Xenova/all-MiniLM-L6-v2') which auto-downloads and caches the ONNX model. The module-level pattern (let pipelineInstance = null) avoids React re-render issues. embedQuery should mean-pool the tensor output the same way as the build script. Wrap initModel() in a try/catch that silently swallows errors."
+    },
+    {
+      "id": "US-005",
+      "title": "Implement cosine similarity search module",
+      "description": "As a developer, I need a semantic search function that compares a query embedding against pre-computed item embeddings and returns ranked results.",
+      "acceptanceCriteria": [
+        "New src/lib/semantic-search.ts module",
+        "Exports semanticSearch(queryEmbedding: number[], embeddings: Array<{ id: string, embedding: number[] }>, threshold?: number): Array<{ id: string, score: number }>",
+        "Uses cosine similarity: dot(a,b) / (magnitude(a) * magnitude(b))",
+        "Results sorted by score descending",
+        "Optional threshold parameter filters out low-relevance results (default 0.3)",
+        "Exports loadEmbeddings() that imports embeddings.json and returns the parsed array",
+        "Typecheck passes"
+      ],
+      "priority": 5,
+      "passes": true,
+      "notes": "Keep the cosine similarity implementation simple — no libraries needed for 384-d vectors over ~40 items. The loadEmbeddings function can use a dynamic import or direct import of the JSON file (Vite handles JSON imports natively)."
+    },
+    {
+      "id": "US-006",
+      "title": "Integrate semantic search into command palette",
+      "description": "As a visitor, I want the command palette to use semantic search when available, falling back to Fuse.js otherwise.",
+      "acceptanceCriteria": [
+        "CommandPalette.tsx checks isModelReady() from embedding-model.ts",
+        "When model is ready and query is non-empty: call embedQuery(query), then semanticSearch() against loaded embeddings, then map result IDs back to PaletteItem objects",
+        "When model is NOT ready: use existing Fuse.js search (current behavior preserved exactly)",
+        "Search is debounced by ~200ms to avoid calling embedQuery on every keystroke",
+        "Results maintain existing groupBySection() grouping and section ordering",
+        "Existing keyboard navigation, action routing, and UI unchanged",
+        "Typecheck passes",
+        "Verify in browser: search 'data analysis' surfaces analytics-related roles/skills not just items with 'data' in title"
+      ],
+      "priority": 6,
+      "passes": true,
+      "notes": "The debounce is important — embedQuery takes ~20-50ms per call. Use a useRef + setTimeout pattern or a simple debounce hook. The mapping from semantic search results (id + score) back to PaletteItems should use a Map for O(1) lookup. Keep the Fuse.js imports and buildSearchIndex — they're the fallback path."
+    },
+    {
+      "id": "US-007",
+      "title": "Chat widget — floating button component",
+      "description": "As a visitor, I see a floating chat button at the bottom-right of the dashboard that I can click to open a chat panel.",
+      "acceptanceCriteria": [
+        "New src/components/ChatWidget.tsx component",
+        "Renders a 48px circular button, fixed position, bottom: 24px, right: 24px",
+        "Uses teal accent background (var(--accent)), white MessageCircle icon from lucide-react",
+        "Shadow: var(--shadow-md). Hover: var(--shadow-lg) + scale(1.05) transition",
+        "Button has a subtle entrance animation: fade + translateY(8px) → translateY(0), delayed ~1s after mount",
+        "Respects prefers-reduced-motion (no animation, just visible)",
+        "z-index above dashboard content but below command palette overlay (z-index 90)",
+        "onClick toggles an isOpen state (panel rendering comes in next story)",
+        "Mounted in DashboardLayout.tsx",
+        "Typecheck passes",
+        "Verify in browser using dev-browser skill"
+      ],
+      "priority": 7,
+      "passes": true,
+      "notes": "Use framer-motion for the entrance animation to match the rest of the app's motion patterns. The button should use font-ui for any text. On mobile (<640px), button is 40px and positioned bottom: 16px, right: 16px. The VITE_GEMINI_API_KEY env var check can wait until the Gemini integration story — for now just render the button unconditionally."
+    },
+    {
+      "id": "US-008",
+      "title": "Chat widget — panel UI with message display",
+      "description": "As a visitor, I want a chat panel that opens above the floating button where I can type questions and see responses.",
+      "acceptanceCriteria": [
+        "Chat panel renders when isOpen is true, positioned above the floating button (bottom: 88px, right: 24px)",
+        "Panel dimensions: 380px wide, max-height 480px, with overflow-y auto for messages",
+        "Header: title text ('Ask about Andy'), close button (X icon)",
+        "Message area: user messages right-aligned in teal-tinted bubbles, assistant messages left-aligned in light gray bubbles",
+        "Input area at bottom: text field with placeholder 'Ask me anything...', send button (Send icon)",
+        "Enter key submits message, Shift+Enter for newline",
+        "Panel entrance animation: scale(0.95) + opacity(0) → scale(1) + opacity(1), 200ms ease-out",
+        "Panel exit animation: reverse of entrance",
+        "Respects prefers-reduced-motion",
+        "Responsive: on mobile (<640px), panel is full-width (left: 0, right: 0, bottom: 0) with rounded top corners only",
+        "Messages are stored in component state as Array<{ role: 'user' | 'assistant', content: string }>",
+        "Submitting a message adds it to state and shows it in the UI (no API call yet — assistant response is a placeholder)",
+        "Typecheck passes",
+        "Verify in browser using dev-browser skill"
+      ],
+      "priority": 8,
+      "passes": true,
+      "notes": "Use the design system tokens: var(--surface) for panel bg, var(--border-light) for borders, var(--text-primary) for text, var(--accent) for user bubble bg at 10% opacity, font-ui for body text, font-geist for timestamps. The placeholder assistant response can be a static string like 'AI chat coming soon — this is a preview of the chat interface.' This lets us verify the full UI before wiring up Gemini."
+    },
+    {
+      "id": "US-009",
+      "title": "Chat widget — Gemini Flash integration",
+      "description": "As a visitor, I can ask natural language questions and get intelligent, streamed answers about Andy's experience.",
+      "acceptanceCriteria": [
+        "New src/lib/gemini.ts module that exports sendChatMessage(messages: ChatMessage[], cvContext: string): AsyncGenerator<string>",
+        "Calls Google Gemini Flash API (gemini-2.0-flash) using the REST API with fetch (no SDK needed)",
+        "API key sourced from import.meta.env.VITE_GEMINI_API_KEY",
+        "System prompt includes structured CV context built from buildEmbeddingTexts() output",
+        "System prompt instructs the model to answer questions about Andy's professional experience accurately and concisely",
+        "System prompt instructs the model to include relevant palette item IDs in its response as a JSON array at the end",
+        "Responses are streamed using the Gemini streaming endpoint",
+        "ChatWidget.tsx wires up real messages: on submit, calls sendChatMessage and streams tokens into the assistant message bubble",
+        "Loading state shown (typing indicator) while waiting for first token",
+        "If VITE_GEMINI_API_KEY is not set, chat button is still visible but panel shows 'Chat is currently unavailable' message",
+        "If API call fails, show error message in chat: 'Sorry, I couldn't process that. Please try again.'",
+        "Conversation history (last 10 messages) passed to API for multi-turn context",
+        "Typecheck passes"
+      ],
+      "priority": 9,
+      "passes": true,
+      "notes": "Gemini REST streaming endpoint: POST https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:streamGenerateContent?alt=sse&key=API_KEY. The response is SSE (server-sent events) — parse each 'data:' line as JSON and extract candidates[0].content.parts[0].text. The system prompt with CV context will be ~2-3K tokens — well within Gemini Flash limits. For the palette item IDs, instruct the model to end its response with a line like [ITEMS: id1, id2, id3] which can be parsed client-side."
+    },
+    {
+      "id": "US-010",
+      "title": "Chat widget — clickable portfolio item cards in responses",
+      "description": "As a visitor, I want AI chat responses to include clickable portfolio items so I can drill into relevant sections.",
+      "acceptanceCriteria": [
+        "After parsing the assistant response, extract referenced palette item IDs from the [ITEMS: ...] suffix",
+        "Render matched items as compact clickable cards below the answer text in the assistant bubble",
+        "Cards reuse icon/color mapping from CommandPalette (iconByType, iconColorStyles)",
+        "Cards show item title and subtitle in a compact horizontal layout",
+        "Clicking a card triggers the same action routing as command palette via handlePaletteAction in DashboardLayout",
+        "If no items are referenced or IDs don't match, no cards are shown (just the text answer)",
+        "Typecheck passes",
+        "Verify in browser using dev-browser skill"
+      ],
+      "priority": 10,
+      "passes": true,
+      "notes": "The action routing needs to flow from ChatWidget up to DashboardLayout. Add an onAction prop to ChatWidget (same pattern as CommandPalette). DashboardLayout passes handlePaletteAction to ChatWidget. Export iconByType and iconColorStyles from CommandPalette (or extract to a shared module) so ChatWidget can reuse them."
+    },
+    {
+      "id": "US-011",
+      "title": "Mobile full-screen chat panel",
+      "description": "As a mobile visitor, I want the chat panel to be a full-screen overlay so it's easy to use on small screens.",
+      "acceptanceCriteria": [
+        "Below md breakpoint (768px), chat panel renders as full-screen overlay using position: fixed; inset: 0 with 100dvh height",
+        "Full-screen mode has the existing header with close button (no visual change needed, just full-width)",
+        "Floating chat button is hidden (display: none or opacity: 0) while panel is open on mobile (<768px)",
+        "Above 768px, existing panel behavior is unchanged (380px wide, anchored bottom-right, max-height 480px)",
+        "Panel open/close animation still respects prefers-reduced-motion",
+        "Safe area insets applied via env(safe-area-inset-*) for notched devices",
+        "Input area stays pinned to bottom of screen on mobile",
+        "Typecheck passes",
+        "Verify in browser using dev-browser skill"
+      ],
+      "priority": 11,
+      "passes": true,
+      "notes": "The current ChatWidget already has some mobile handling (bottom-sheet style at <640px). This story changes the breakpoint to 768px (md) and makes it truly full-screen instead of 85vh. Use 100dvh (dynamic viewport height) to account for mobile browser chrome. The floating button visibility can be controlled by combining isOpen state with a CSS media query or a useMediaQuery hook. The <style> block with data-chat-panel attribute is the place to update responsive rules."
+    },
+    {
+      "id": "US-012",
+      "title": "Welcome message with suggested question chips",
+      "description": "As a visitor opening the chat, I see a friendly welcome message and clickable suggested questions so I know what to ask.",
+      "acceptanceCriteria": [
+        "When chat panel is open and conversation is empty, display welcome text: 'Hey! I'm here to help you learn more about Andy. What would you like to know?'",
+        "Welcome text is styled as an AI message bubble (left-aligned, light background, same styling as assistant messages)",
+        "Below the welcome bubble, show 2-3 clickable pill/chip buttons with suggested questions",
+        "Suggested questions: 'What's his NHS experience?', 'Tell me about his data skills', 'What projects has he built?'",
+        "Chips styled with: teal accent border, rounded-full, font-ui 12-13px, hover state (teal background tint)",
+        "Clicking a chip sends that question as a user message (same codepath as typing + Enter)",
+        "Welcome message and chips always visible when conversation is empty (persist across panel open/close)",
+        "Once any message is sent, the welcome/chips area is replaced by the conversation messages",
+        "Typecheck passes",
+        "Verify in browser using dev-browser skill"
+      ],
+      "priority": 12,
+      "passes": true,
+      "notes": "Replace the current empty-state text ('Ask me anything about Andy's experience, skills, or projects.') with the new welcome bubble + chips. The chips should call handleSubmit (or equivalent) with the chip text pre-filled — simplest approach is setInputValue(chipText) then immediately trigger submit. Check that the welcome state reappears if the user hasn't sent a message (messages.length === 0). The suggested questions could live in a const array at the top of ChatWidget for easy future editing."
+    },
+    {
+      "id": "US-013",
+      "title": "Self-host ONNX embedding model",
+      "description": "As a developer, I want the ONNX model files served from the same host as the site to eliminate dependency on Hugging Face CDN.",
+      "acceptanceCriteria": [
+        "Model files for Xenova/all-MiniLM-L6-v2 downloaded and placed in public/models/all-MiniLM-L6-v2/onnx/ (matching HF repo structure)",
+        "Required files present: model_quantized.onnx, tokenizer.json, tokenizer_config.json, config.json, and any other files the pipeline expects",
+        "src/lib/embedding-model.ts updated: configure @xenova/transformers env to use local model path (e.g., env.localModelPath or custom model URL pointing to /models/)",
+        "scripts/generate-embeddings.ts also updated to use the same local model path for consistency",
+        "Model files are NOT in .gitignore — they are committed as static assets",
+        "No network requests to huggingface.co in the browser network tab when semantic search is used",
+        "Semantic search still works correctly in the command palette after the change",
+        "Typecheck passes"
+      ],
+      "priority": 13,
+      "passes": true,
+      "notes": "Transformers.js uses env.localModelPath or env.remoteHost to control where models are fetched from. Setting env.localModelPath = '/models/' should make it look for files at /models/Xenova/all-MiniLM-L6-v2/onnx/model_quantized.onnx etc. The Vite public/ directory serves files at the root — so public/models/ becomes /models/ at runtime. For the build script (Node.js), use a file:// path or the local filesystem path instead. Download model files from https://huggingface.co/Xenova/all-MiniLM-L6-v2/tree/main — the quantized ONNX model is ~23MB. Check what files the pipeline actually requests by watching network tab before making this change."
+    },
+    {
+      "id": "US-014",
+      "title": "Migrate production chat from Gemini to OpenRouter",
+      "description": "As a developer, I need to replace the Gemini API integration with OpenRouter so the chat uses z-ai/glm-5.",
+      "acceptanceCriteria": [
+        "Rename src/lib/gemini.ts to src/lib/llm.ts",
+        "Update all imports across the codebase (ChatWidget.tsx, search.ts, any other files importing from gemini.ts)",
+        "Replace Gemini API calls with OpenRouter's OpenAI-compatible API (POST https://openrouter.ai/api/v1/chat/completions)",
+        "Model set to z-ai/glm-5 in request body",
+        "API key read from import.meta.env.VITE_OPEN_ROUTER_API_KEY via Authorization: Bearer header",
+        "Include HTTP-Referer and X-Title headers as recommended by OpenRouter docs",
+        "SSE streaming works using OpenRouter's stream: true option (parse choices[0].delta.content from each SSE data line)",
+        "System prompt sent as first message with role: 'system' (OpenAI chat completions format)",
+        "Message history uses role: 'user' | 'assistant' (no 'model' mapping needed — already correct)",
+        "Export updated constant: LLM_DISPLAY_NAME = 'GLM-5' and update ChatWidget model indicator text",
+        "Rename isGeminiAvailable() to isLLMAvailable() and update all call sites",
+        "Typecheck passes",
+        "Verify in browser: chat opens, sends a message, streams a response correctly"
+      ],
+      "priority": 14,
+      "passes": true,
+      "notes": "OpenRouter uses the OpenAI-compatible format. Key differences from Gemini: (1) Auth via Bearer token header, not URL param. (2) System prompt is a message with role:'system', not a separate system_instruction field. (3) Streaming SSE data lines contain {choices:[{delta:{content:'...'}}]}, not candidates[0].content.parts[0].text. (4) The [DONE] sentinel is the same. (5) Add headers: 'HTTP-Referer': window.location.origin, 'X-Title': 'Andy Charlwood Portfolio'. The buildSystemPrompt() function and its content stay the same — only the API transport changes. The buildRequestBody() function needs the most changes."
+    },
+    {
+      "id": "US-015",
+      "title": "Migrate benchmark script to OpenRouter",
+      "description": "As a developer, I need the benchmark harness to use OpenRouter so it tests the same model and prompt path as production.",
+      "acceptanceCriteria": [
+        "scripts/benchmark.ts uses OpenRouter API (POST https://openrouter.ai/api/v1/chat/completions) instead of Gemini",
+        "API key read from process.env.VITE_OPEN_ROUTER_API_KEY (loaded from .env file)",
+        "Request body uses OpenAI chat completions format: messages array with system/user roles",
+        "Model set to z-ai/glm-5 in request body",
+        "Auth via Authorization: Bearer header (not URL param)",
+        "Rate limit retry logic updated for OpenRouter error responses (429 status)",
+        "Response parsing updated: extract choices[0].message.content (non-streaming endpoint)",
+        "Scoring calls also use OpenRouter with same model",
+        "Model name in results output updated to z-ai/glm-5",
+        "npm run benchmark runs end-to-end without errors",
+        "Typecheck passes"
+      ],
+      "priority": 15,
+      "passes": true,
+      "notes": "The benchmark uses the non-streaming endpoint (no stream:true needed). OpenRouter non-streaming response format: { choices: [{ message: { content: '...' } }] }. The buildSystemPrompt() function should be imported from the renamed llm.ts (or duplicated if the import path alias doesn't work in tsx scripts — check if @/ alias resolves). Keep the same retry logic structure but update status code handling for OpenRouter. The scoring prompt and question flow are unchanged — only the API transport layer changes."
+    },
+    {
+      "id": "US-016",
+      "title": "Enrich system prompt with full CV context",
+      "description": "As a portfolio visitor, I want the AI to have comprehensive knowledge of Andy's background so it can answer detailed questions accurately.",
+      "acceptanceCriteria": [
+        "buildSystemPrompt() in llm.ts includes full professional profile narrative from CV_v4.md",
+        "Each role includes full achievement bullets, not just the summary text from buildEmbeddingTexts()",
+        "Clear section headers in the prompt: Professional Profile, Career History (per role with dates/employer), Education, Skills, Projects",
+        "NHS employment (May 2022+) explicitly distinguished from private sector (Tesco PLC)",
+        "Clinical specialties listed under the relevant role (rheumatology, ophthalmology, dermatology, etc.)",
+        "Methodology details included (e.g., how the switching algorithm worked, what dm+d integration involved)",
+        "Education includes specific grades, subjects, research topics, classifications",
+        "Leadership training (Mary Seacole Programme) included with year and result",
+        "No invented or extrapolated content — everything sourced from CV_v4.md and data files",
+        "System prompt remains under 8KB total",
+        "Typecheck passes"
+      ],
+      "priority": 16,
+      "passes": true,
+      "notes": "The current system prompt uses buildEmbeddingTexts() which gives one paragraph per palette item — good for embeddings but too compressed for detailed Q&A. The enriched prompt should read more like a structured CV with full bullet points. Source content from References/CV_v4.md — read the file to extract all detail. Consider structuring as: ## Profile (personal statement), ## Career History (each role as ### with bullets), ## Education (each qualification), ## Projects (each project with tech and outcomes). Keep it well-structured with markdown headers — LLMs parse this better than flat text."
+    },
+    {
+      "id": "US-017",
+      "title": "Improve system prompt instructions and LLM parameters",
+      "description": "As a portfolio visitor, I want the AI to cite specifics, distinguish between employers, and aggregate across roles when asked.",
+      "acceptanceCriteria": [
+        "Prompt instructs LLM to distinguish NHS employment (ICB, May 2022+) from private sector (Tesco PLC, community pharmacy)",
+        "Prompt instructs LLM to aggregate across roles when asked broad questions (e.g., 'what tools has Andy built?' should list tools from ALL roles)",
+        "Prompt instructs LLM to cite specific metrics, dates, and outcomes when available rather than being vague",
+        "Prompt instructs LLM to answer from the provided context only and say so when information isn't available",
+        "Temperature lowered from 0.7 to 0.3-0.5 for more consistent factual responses",
+        "maxOutputTokens increased from 512 to at least 768 to avoid truncating detailed answers",
+        "The [ITEMS: ...] suffix instruction is preserved and clear",
+        "Typecheck passes"
+      ],
+      "priority": 17,
+      "passes": true,
+      "notes": "These are behavioral instructions that go in the Rules section of the system prompt. Keep them concise — LLMs follow shorter, clearer rules better than long paragraphs. Consider: '1. Distinguish NHS employment (May 2022–present, ICB) from private sector (Tesco PLC). 2. When asked about tools/skills across career, aggregate from ALL roles. 3. Cite specific numbers, dates, and outcomes — never say approximate when exact figures are available. 4. If the answer isn't in the context, say so clearly.' Temperature and maxTokens are set in the API request config, not the prompt."
+    },
+    {
+      "id": "US-018",
+      "title": "Enrich embedding texts and regenerate embeddings",
+      "description": "As a portfolio visitor, I want semantic search to surface relevant results even for nuanced queries by having richer embedding texts.",
+      "acceptanceCriteria": [
+        "buildEmbeddingTexts() in search.ts generates richer text per item with full achievement narratives, methodology detail, and clinical specialties",
+        "Role history narratives are included (currently only examination bullets and codedEntries may be used)",
+        "Cross-references included where items relate (e.g., CD monitoring project links to controlled drugs skill)",
+        "Embedding texts remain well-formed natural language (not keyword soup)",
+        "Embeddings regenerated by running npm run generate-embeddings",
+        "Output written to src/data/embeddings.json",
+        "Number of embeddings matches number of palette items (currently 42)",
+        "Typecheck passes"
+      ],
+      "priority": 18,
+      "passes": true,
+      "notes": "This combines the PRD's US-005 (enrich texts) and US-006 (regenerate embeddings) since they must happen together. Review what buildEmbeddingTexts() currently produces and identify gaps — the benchmark questions highlight what's missing (e.g., clinical specialties, methodology detail, dm+d context, employer classification). After modifying the texts, run npm run generate-embeddings to regenerate. Verify the embedding count matches before and after."
+    },
+    {
+      "id": "US-019",
+      "title": "Run benchmark and validate accuracy",
+      "description": "As a developer, I want to run the benchmark against the enriched prompt and verify the pass threshold is met.",
+      "acceptanceCriteria": [
+        "Run npm run benchmark successfully against OpenRouter with enriched system prompt",
+        "Score 18/20 or higher (90%+ accuracy) on the 10 benchmark questions",
+        "No question scores 0 (no factual errors)",
+        "Results saved to scripts/benchmark-results/ as a timestamped iteration file",
+        "Additionally test 5 general questions manually or via script: 'Tell me about Andy', 'What does Andy do?', 'How can I contact Andy?', 'What is this website?', 'What are Andy's strongest skills?'",
+        "General questions produce sensible, accurate responses without degradation",
+        "If benchmark fails threshold, identify failing questions and make structural improvements to the prompt (not question-specific hacks), then re-run",
+        "Final passing results saved as evidence"
+      ],
+      "priority": 19,
+      "passes": true,
+      "notes": "This is the iterative loop. In a single Ralph iteration, run the benchmark, review results, and if needed make targeted improvements to the system prompt in llm.ts. Focus on structural fixes: if Q7 (clinical specialties) fails, ensure the system prompt lists specialties under the relevant role — this helps ALL specialty questions, not just Q7. If the benchmark takes too many iterations, focus on getting the most impactful improvements in and document remaining gaps. The anti-benchmaxing rules apply: no hardcoded answers, no question-specific prompt clauses."
+    }
+  ]
+}

Ralph/archive/2026-02-16-llm-cv-knowledge/progress.txt

@@ -0,0 +1,464 @@
+# Progress Log — Semantic Search & AI Chat
+# Branch: ralph/semantic-search
+# Started: 2026-02-15
+
+## Codebase Patterns
+- `@xenova/transformers` pipeline with `pooling: 'mean'` and `normalize: true` returns a Tensor; use `Array.from(output.data as Float32Array)` to extract the 384-d vector
+- Scripts live in `scripts/` and run via `npx tsx` (tsx is not a project dep, npx fetches it)
+- tsconfig `include` only covers `src/` — scripts are type-checked by tsx at runtime, not by `tsc --noEmit`
+- Project uses `"type": "module"` in package.json
+- Palette item IDs: `exp-{consultation.id}`, `skill-{skill.id}`, `proj-{investigation.id}`, `ach-{0-3}`, `edu-{0-3}`, `action-{0-3}`
+- `buildEmbeddingTexts()` in `src/lib/search.ts` returns `Array<{ id: string, text: string }>` with IDs matching PaletteItem IDs — use this for both embedding generation and chat context
+- `src/data/embeddings.json` is an array of `{ id: string, embedding: number[] }` — 42 items, 384-d vectors, IDs match PaletteItem IDs. Vite imports JSON natively.
+- `src/lib/embedding-model.ts` exports `initModel()`, `embedQuery(text)`, `isModelReady()` — check `isModelReady()` before calling `embedQuery()`
+- `initModel()` is called fire-and-forget in `App.tsx` on mount — model loads during boot/ECG/login phases
+- ONNX model files self-hosted in `public/models/Xenova/all-MiniLM-L6-v2/` — `env.localModelPath = '/models/'`, `env.allowRemoteModels = false`, `env.useBrowserCache = false` eliminates HF CDN dependency
+- `src/lib/semantic-search.ts` exports `semanticSearch(queryEmbedding, embeddings, threshold?)` and `loadEmbeddings()` — embeddings are normalized so cosine similarity is dot(a,b)/(mag(a)*mag(b))
+- CommandPalette uses `semanticResults` state + debounced `useEffect` for async semantic search, falling back to Fuse.js when `isModelReady()` returns false or on any error
+- `loadEmbeddings()` and `paletteMap` (Map<id, PaletteItem>) are precomputed via `useMemo` — no re-computation on each search
+- ChatWidget is mounted in DashboardLayout alongside CommandPalette and DetailPanel — z-index 90 (below command palette z-1000)
+- `prefersReducedMotion` pattern: read `window.matchMedia` at module level, use in framer-motion variants to skip animation
+- ChatWidget stores messages as `Array<{ role: 'user' | 'assistant', content: string }>` — same shape as LLM message format
+- ChatWidget `isOpen` state controls both panel visibility and button icon (MessageCircle ↔ X) — panel rendering handled by AnimatePresence
+- `src/lib/llm.ts` exports `sendChatMessage(messages)` (async generator), `isLLMAvailable()`, `buildSystemPrompt()`, `parseItemIds(text)`, `stripItemsSuffix(text)`, `LLM_MODEL`, `LLM_DISPLAY_NAME` — ChatMessage type is `{ role: 'user' | 'assistant', content: string }`
+- LLM API uses OpenRouter (OpenAI-compatible): POST to `https://openrouter.ai/api/v1/chat/completions` with `stream: true`, auth via `Authorization: Bearer` header, parse SSE `data:` lines as JSON, extract `choices[0].delta.content`
+- System prompt sent as `role: 'system'` message (first in messages array), built from `buildEmbeddingTexts()` — instructs model to end responses with `[ITEMS: id1, id2, id3]` for portfolio item linking
+- `isLLMAvailable()` checks `import.meta.env.VITE_OPEN_ROUTER_API_KEY` — when missing, chat panel shows "unavailable" message but button remains visible
+- OpenRouter requires `HTTP-Referer` and `X-Title` headers — set to `window.location.origin` and `'Andy Charlwood Portfolio'` respectively
+- Model is `z-ai/glm-5` (set in `LLM_MODEL` constant in `llm.ts`)
+- Assistant messages store item IDs as `<!--ITEMS:id1,id2-->` HTML comment suffix for US-010 to parse — `getDisplayText()` strips this before rendering
+- Conversation history capped at 10 messages (`MAX_HISTORY`), metadata stripped before sending to API
+- Icon/color mappings (`iconByType`, `iconColorStyles`) live in `src/lib/palette-icons.ts` — shared between CommandPalette and ChatWidget
+- ChatWidget accepts optional `onAction?: (action: PaletteAction) => void` prop — same pattern as CommandPalette's `onAction`
+- `DashboardLayout` passes `handlePaletteAction` to both CommandPalette and ChatWidget for unified action routing
+- TopBar is `z-index: 100` (fixed), nav is `z-index: 99` (sticky) — mobile full-screen overlays need `z-index > 100` to appear above them
+- Inline `style={{ display: 'flex' }}` overrides Tailwind's `hidden` class — use `!important` modifier (`max-md:!hidden`) or move display to Tailwind classes to allow responsive hiding
+- ChatWidget mobile breakpoint is `md` (768px) — below this, panel is full-screen; above, it's 380px anchored bottom-right
+- `handleSubmit(overrideText?)` accepts optional text param — use this when programmatically sending messages (e.g., suggested question chips) to avoid stale `inputValue` state
+- `SUGGESTED_QUESTIONS` const array at top of ChatWidget — edit here to change welcome screen chip text
+- System prompt prefixes each CV entry with `[item-id]` so the model can directly reference IDs in its `[ITEMS: ...]` suffix — more reliable than expecting pattern inference
+- Benchmark script (`scripts/benchmark.ts`) uses OpenRouter non-streaming endpoint — response format: `choices[0].message.content` (not `.delta.content` like streaming). Auth via `Authorization: Bearer` header, API key from `process.env.VITE_OPEN_ROUTER_API_KEY`
+- Cannot import `buildSystemPrompt` from `src/lib/llm.ts` into Node scripts — `llm.ts` uses `import.meta.env` (Vite) and `window.location` (browser). Benchmark keeps its own copy of `buildSystemPrompt` that mirrors production
+- `buildEmbeddingTexts()` uses `skillContextMap` and `projectContextMap` Record objects to enrich each item with role context, cross-references, and practical application detail — edit these maps when adding new skills/projects
+- System prompt has an **Employment Timeline (IMPORTANT)** section that explicitly separates NHS from private sector — this is critical for preventing employer conflation. System prompt must stay under 8KB.
+- Benchmark config `scripts/benchmark-config.json` expected answers must accurately reflect the source CV data — ambiguous expected answers cause false negatives in scoring
+
+---
+
+## 2026-02-15 - US-001
+- Installed `@xenova/transformers` (^2.17.2)
+- Created `scripts/generate-embeddings.ts` with main() that loads `Xenova/all-MiniLM-L6-v2` and embeds a test string
+- Added `"generate-embeddings"` npm script
+- Verified: outputs vector length 384 and exits cleanly
+- Typecheck passes
+- Files changed: `package.json`, `package-lock.json`, `scripts/generate-embeddings.ts`
+- **Learnings for future iterations:**
+  - `pipeline('feature-extraction', 'Xenova/all-MiniLM-L6-v2')` auto-downloads and caches the ONNX model (~23MB)
+  - First run takes a few seconds for model download; subsequent runs are near-instant from cache
+  - The pipeline's `pooling: 'mean'` and `normalize: true` options handle mean-pooling and L2 normalization in one step — no manual tensor manipulation needed
+  - `output.data` is a `Float32Array`; wrap in `Array.from()` for a plain number array
+---
+
+## 2026-02-15 - US-002
+- Added `buildEmbeddingTexts()` function to `src/lib/search.ts`
+- Imports all raw data files (consultations, skills, kpis, investigations, documents)
+- Generates natural-language paragraphs for each palette item type:
+  - Consultations: role, org, duration, history narrative, examination bullets, coded entry descriptions
+  - Skills: name, category, frequency, proficiency %, years of experience
+  - Achievements: title, subtitle, full KPI explanation + story context + outcomes
+  - Investigations: name, methodology, tech stack, results
+  - Education: title, type, institution, duration, classification, research detail, notes (from documents.ts)
+  - Quick Actions: title + subtitle
+- IDs match PaletteItem IDs (e.g. `exp-{id}`, `skill-{id}`, `ach-{i}`, `proj-{id}`, `edu-{i}`, `action-{i}`)
+- Typecheck and lint pass
+- Files changed: `src/lib/search.ts`
+- **Learnings for future iterations:**
+  - Education items in `buildPaletteData()` are hardcoded arrays (not iterated from `documents`), with ids `edu-0` through `edu-3`. The mapping to `documents.ts` entries is: edu-0→doc-mary-seacole, edu-1→doc-mpharm, edu-2→doc-alevels, edu-3→doc-gphc
+  - Achievement items are similarly hardcoded with ids `ach-0` through `ach-3`, each linked to a KPI id
+  - Quick action items are `action-0` through `action-3`
+  - `documents.ts` is imported but wasn't previously used in `search.ts` — now used for education embedding text
+---
+
+## 2026-02-15 - US-003
+- Updated `scripts/generate-embeddings.ts` to import `buildEmbeddingTexts()` and generate full embeddings
+- Script embeds all 42 palette items sequentially using `Xenova/all-MiniLM-L6-v2`
+- Outputs `src/data/embeddings.json` as `Array<{ id: string, embedding: number[] }>`
+- Each embedding is a 384-dimensional float array
+- File is ~453KB (42 items × 384 floats with pretty-printed JSON)
+- `npm run generate-embeddings` regenerates the file successfully
+- Typecheck and lint pass
+- Files changed: `scripts/generate-embeddings.ts`, `src/data/embeddings.json`
+- **Learnings for future iterations:**
+  - `import.meta.dirname` works in tsx/Node ESM scripts — use it instead of `__dirname` (which isn't available in ESM)
+  - `@/` path alias works in `npx tsx` scripts because tsx resolves tsconfig paths automatically
+  - The embeddings file is ~450KB with pretty-print; could be reduced with compact JSON but readability is preferred for now
+  - Processing 42 items takes ~10-15 seconds on first run (model cached after first download)
+---
+
+## 2026-02-15 - US-004
+- Created `src/lib/embedding-model.ts` with three exports: `initModel()`, `embedQuery()`, `isModelReady()`
+- Module-level `let extractor` pattern avoids React re-render issues
+- `initModel()` uses `loading` guard to prevent duplicate pipeline loads
+- `embedQuery()` uses same `pooling: 'mean'` and `normalize: true` as the build script
+- `initModel()` called fire-and-forget in `App.tsx` `useEffect([], [])` — runs during boot phase
+- Silent failure: try/catch swallows errors, `isModelReady()` stays false
+- Typecheck, lint, and build all pass
+- Files changed: `src/lib/embedding-model.ts` (new), `src/App.tsx`
+- **Learnings for future iterations:**
+  - `FeatureExtractionPipeline` type is exported from `@xenova/transformers` and can be used for the module-level variable
+  - The `loading` boolean guard prevents race conditions if `initModel()` is called multiple times (e.g., React strict mode double-mount)
+  - `initModel()` is intentionally not awaited — it's fire-and-forget so it doesn't block the boot animation
+  - Consumers should check `isModelReady()` before calling `embedQuery()` — it throws if model isn't loaded
+---
+
+## 2026-02-15 - US-005
+- Created `src/lib/semantic-search.ts` with cosine similarity search and embeddings loader
+- `semanticSearch()` computes cosine similarity, filters by threshold (default 0.3), returns sorted by score descending
+- `loadEmbeddings()` imports `embeddings.json` via Vite's native JSON import and returns typed array
+- Typecheck and lint pass (0 new warnings)
+- Files changed: `src/lib/semantic-search.ts` (new)
+- **Learnings for future iterations:**
+  - Vite handles JSON imports natively — `import data from '@/data/embeddings.json'` just works, no dynamic import needed
+  - Since embeddings are already L2-normalized (from pipeline's `normalize: true`), cosine similarity simplifies to just the dot product. However, the full formula is kept for correctness in case non-normalized vectors are ever used
+  - With only ~42 items and 384-d vectors, brute-force cosine similarity is fast enough — no need for approximate nearest neighbor libraries
+---
+
+## 2026-02-15 - US-006
+- Integrated semantic search into CommandPalette with Fuse.js fallback
+- When `isModelReady()` is true: debounces query by 200ms, calls `embedQuery()`, runs `semanticSearch()` against preloaded embeddings, maps result IDs back to PaletteItems via O(1) Map lookup
+- When model is NOT ready: uses existing Fuse.js search (behavior preserved exactly)
+- Results maintain `groupBySection()` grouping and section ordering
+- Existing keyboard navigation, action routing, and UI unchanged
+- Semantic results state is cleared when palette opens/closes and when query is empty
+- Error handling: any failure in embedQuery/semanticSearch silently falls back to Fuse.js
+- Typecheck, lint, and build all pass
+- Browser verified: Fuse.js fallback works correctly; ONNX model loads asynchronously during boot and activates semantic search when ready
+- Files changed: `src/components/CommandPalette.tsx`
+- **Learnings for future iterations:**
+  - Semantic search is async so it can't live in a `useMemo` — use `useState` + debounced `useEffect` pattern instead
+  - The `useRef + setTimeout` debounce pattern works well here: set `debounceRef.current = setTimeout(...)`, clear it in the cleanup function, and in early-return paths
+  - `isModelReady()` is a synchronous check — call it before setting up the debounce timeout to avoid unnecessary delays when model isn't loaded
+  - The ONNX model takes several seconds to load in the browser (downloads ~23MB first time, then cached in IndexedDB), so initial searches will always use Fuse.js fallback
+  - `loadEmbeddings()` is cheap (just returns the already-imported JSON) — safe to call in `useMemo` without performance concern
+---
+
+## 2026-02-15 - US-007
+- Created `src/components/ChatWidget.tsx` — floating chat button with toggle state
+- 48px circular button (40px on mobile <640px), fixed bottom-right, teal accent background, white MessageCircle icon
+- Entrance animation: fade + translateY(8px→0), 1s delay after mount, via framer-motion variants
+- Respects `prefers-reduced-motion` — skips animation, shows immediately
+- Hover: shadow-md → shadow-lg + scale(1.05), 150ms transition
+- z-index 90 (below command palette z-1000)
+- onClick toggles `isOpen` state, swaps icon between MessageCircle and X
+- Mounted in `DashboardLayout.tsx` alongside CommandPalette and DetailPanel
+- Typecheck, lint (0 errors), and build all pass
+- Browser verified: button visible at bottom-right, toggle works (Open chat ↔ Close chat)
+- Files changed: `src/components/ChatWidget.tsx` (new), `src/components/DashboardLayout.tsx`
+- **Learnings for future iterations:**
+  - Responsive sizing via Tailwind classes (`h-10 w-10 sm:h-12 sm:w-12`) works well with inline style for non-Tailwind properties (boxShadow, border-radius)
+  - `AnimatePresence` is already imported and ready for the panel animation in US-008
+  - The `isOpen` state lives in ChatWidget — US-008 will add the panel UI inside the same component
+  - Hover effects use `onMouseEnter/Leave` with direct style mutation (same pattern as other dashboard components)
+---
+
+## 2026-02-15 - US-008
+- Built chat panel UI inside `ChatWidget.tsx` with header, message area, and input
+- Panel opens above the floating button with scale+opacity entrance/exit animation via framer-motion `AnimatePresence`
+- Messages stored as `Array<{ role: 'user' | 'assistant', content: string }>` in component state
+- User messages right-aligned in teal-tinted bubbles (`var(--accent-light)` bg, `var(--accent-border)` border)
+- Assistant messages left-aligned in light gray bubbles (`var(--bg-dashboard)` bg, `var(--border-light)` border)
+- Message corner radii differ: user bubbles have small bottom-right radius, assistant bubbles small bottom-left (conversational feel)
+- Input area: textarea with Enter to submit, Shift+Enter for newline. Send button enabled/disabled based on input content
+- Empty state shows placeholder text when no messages yet
+- Auto-scrolls to latest message via `useRef` + `scrollIntoView`
+- Auto-focuses input when panel opens (200ms delay for animation)
+- Responsive: on mobile (<640px), panel is full-width bottom sheet with rounded top corners; on desktop, 380px wide positioned above the button
+- Panel entrance: scale(0.95)+opacity(0) → scale(1)+opacity(1), 200ms. Exit: reverse, 150ms
+- Respects `prefers-reduced-motion` — skips all animation
+- Close button in header triggers `setIsOpen(false)` (same as floating button toggle)
+- Submitting appends both user message and placeholder assistant response to state
+- Typecheck, lint (0 errors), and build all pass
+- Browser verified: panel opens/closes correctly, messages display, input works, Enter submits, close button works
+- Files changed: `src/components/ChatWidget.tsx`
+- **Learnings for future iterations:**
+  - `AnimatePresence` with `key` prop on the panel div is needed for exit animations to work
+  - Panel uses `transformOrigin: 'bottom right'` for natural scale animation from the button corner
+  - CSS-in-JS `<style>` tag with `data-chat-panel` attribute handles responsive width/height (Tailwind can't express max-height conditionally based on viewport width easily)
+  - `textarea` with `rows={1}` and `maxHeight: 80px` gives auto-growing feel; `resize: none` prevents manual resize
+  - The `ChatMessage` interface (`{ role, content }`) is ready to be extended for US-009 Gemini integration — same shape as typical LLM message format
+  - `onFocus/onBlur` border color transitions on the textarea give a polished input interaction
+---
+
+## 2026-02-15 - US-009
+- Created `src/lib/gemini.ts` — Gemini Flash streaming integration module
+  - `sendChatMessage(messages)` async generator that streams SSE tokens from Gemini 2.0 Flash
+  - `isGeminiAvailable()` checks for `VITE_GEMINI_API_KEY` env var
+  - `parseItemIds(text)` extracts `[ITEMS: id1, id2]` from response text
+  - `stripItemsSuffix(text)` removes the `[ITEMS: ...]` line for clean display
+  - System prompt built from `buildEmbeddingTexts()` output — full CV context (~42 items)
+  - Model instructed to answer concisely and append relevant palette item IDs
+- Rewired `ChatWidget.tsx` to use real Gemini API instead of placeholder responses
+  - Streaming: tokens progressively appear in assistant message bubble
+  - Typing indicator (Loader2 spinner + "Thinking...") shown while waiting for first token
+  - Input disabled during streaming, send button grayed out
+  - Error handling: API failures show "Sorry, I couldn't process that. Please try again."
+  - Missing API key: panel shows "Chat is currently unavailable", input area hidden
+  - Conversation history capped at 10 messages before sending to API
+  - Assistant messages store parsed item IDs as `<!--ITEMS:id1,id2-->` HTML comment (for US-010)
+  - Messages sent to API have metadata stripped to keep context clean
+- Typecheck, lint (0 errors), and build all pass
+- Files changed: `src/lib/gemini.ts` (new), `src/components/ChatWidget.tsx`
+- **Learnings for future iterations:**
+  - Gemini SSE format: `data:` prefix per line, JSON body with `candidates[0].content.parts[0].text`
+  - `system_instruction` field in Gemini request body sets the system prompt (not a message in `contents`)
+  - Gemini role mapping: `'assistant'` → `'model'` in the API's `contents` array
+  - Buffer-based SSE parsing handles chunk boundaries: split on `\n`, keep last incomplete line in buffer
+  - `buildEmbeddingTexts()` is a great source for structured CV context — natural language paragraphs per item
+  - The `<!--ITEMS:-->` HTML comment pattern is invisible when rendered but parseable by US-010 for item card display
+  - `useCallback` on `handleSubmit` with `[inputValue, isStreaming, messages]` deps is needed because it reads all three
+---
+
+## 2026-02-15 - US-010
+- Extracted `iconByType` and `iconColorStyles` from `CommandPalette.tsx` into shared `src/lib/palette-icons.ts`
+- Updated `CommandPalette.tsx` to import from the shared module (no behavioral change)
+- Added `onAction?: (action: PaletteAction) => void` prop to `ChatWidget` — same pattern as `CommandPalette`
+- `DashboardLayout.tsx` passes `handlePaletteAction` to `ChatWidget` (same handler used by CommandPalette)
+- ChatWidget builds a `paletteMap` (Map<id, PaletteItem>) via `useMemo` for O(1) item lookups
+- Added `getMessageItemIds()` to parse `<!--ITEMS:id1,id2-->` HTML comments from message content
+- Added `getMessageItems()` to resolve parsed IDs to PaletteItem objects via the map
+- Assistant message bubbles now render compact clickable item cards below text when items are referenced:
+  - Cards use same icon/color scheme from CommandPalette (22px icon + title + subtitle)
+  - Cards have hover highlight (`var(--accent-light)`) and trigger `onAction(item.action)` on click
+  - Cards only appear after streaming completes (when `<!--ITEMS:-->` metadata is in final content)
+  - If no items referenced or IDs don't match, no cards shown — just text
+- Typecheck, lint (0 errors), and build all pass
+- Files changed: `src/lib/palette-icons.ts` (new), `src/components/ChatWidget.tsx`, `src/components/CommandPalette.tsx`, `src/components/DashboardLayout.tsx`
+- **Learnings for future iterations:**
+  - Extracting shared constants to `src/lib/` is the right pattern — both `CommandPalette` and `ChatWidget` now use the same icon mappings without duplication
+  - `buildPaletteData()` is pure (no side effects) and idempotent — safe to call in `useMemo` with empty deps
+  - The `<!--ITEMS:-->` HTML comment regex `<!--ITEMS:([^>]*)-->` works reliably; `[^>]*` captures everything between the colons and closing
+  - Item card buttons use `fontFamily: 'inherit'` to pick up the panel's `font-ui` — without this, browser defaults apply
+  - The `overflow: 'hidden'` on the message bubble container is needed so the item cards section (with its own border-top) stays visually contained within the bubble's border-radius
+---
+
+## 2026-02-15 - US-011
+- Updated ChatWidget mobile breakpoint from `sm` (640px) to `md` (768px)
+- Changed mobile panel from 85vh bottom-sheet to full-screen overlay using `position: fixed; inset: 0` with `100dvh` height
+- Panel z-index on mobile bumped to 101 (`max-md:z-[101]`) to render above TopBar (z-100) and nav (z-99)
+- Floating chat button hidden on mobile when panel is open via `max-md:!hidden` Tailwind class
+  - Fixed specificity issue: inline `style={{ display: 'flex' }}` was overriding Tailwind's `hidden` — moved flex/centering to Tailwind classes (`flex items-center justify-center`)
+- Safe area insets applied via `env(safe-area-inset-*)` CSS on the `[data-chat-panel]` element for notched devices
+- Input area stays pinned to bottom via existing flex layout (flex-col container + flex-1 message area + flex-shrink-0 input)
+- Desktop behavior unchanged: 380px wide, anchored bottom-right, max-height 480px, floating button visible
+- Panel open/close animations still respect `prefers-reduced-motion`
+- Typecheck, lint (0 errors), and build all pass
+- Browser verified at 375×812 (mobile) and 1280×800 (desktop): full-screen overlay works, button hides/shows correctly, close button works
+- Files changed: `src/components/ChatWidget.tsx`
+- **Learnings for future iterations:**
+  - Inline `style` properties always override CSS classes — to allow Tailwind responsive utilities (like `max-md:hidden`) to work, move conflicting properties (especially `display`) to Tailwind classes instead
+  - Use `!important` modifier (`max-md:!hidden`) when competing with framer-motion's inline styles that can't be easily removed
+  - TopBar (`z-100`) and nav (`z-99`) sit above the chat panel's default `z-90` — mobile full-screen panels need `z-101+` to overlay properly
+  - `100dvh` (dynamic viewport height) is essential for mobile full-screen panels — it accounts for browser chrome (address bar, toolbar) unlike `100vh`
+  - The `[data-chat-panel]` CSS selector in the `<style>` block is the right place for responsive size rules since Tailwind can't conditionally set max-height based on viewport width
+---
+
+## 2026-02-15 - US-012
+- Replaced empty-state centered text with welcome bubble + suggested question chips
+- Welcome bubble styled as assistant message (left-aligned, `var(--bg-dashboard)` bg, `var(--border-light)` border)
+- Added `SUGGESTED_QUESTIONS` const array at module top for easy future editing
+- Three chips: "What's his NHS experience?", "Tell me about his data skills", "What projects has he built?"
+- Chips styled: rounded-full, teal accent border, teal hover tint, `font-ui` 12.5px
+- Clicking a chip calls `handleSubmit(questionText)` — same codepath as typing + Enter
+- Refactored `handleSubmit` to accept optional `overrideText` parameter (avoids stale state issue with `setInputValue` + immediate submit)
+- Wrapped send button `onClick` in arrow function to prevent passing MouseEvent as text argument
+- Welcome/chips visible when `messages.length === 0`, replaced by conversation once any message is sent
+- Typecheck passes (0 errors), lint passes (0 new errors/warnings)
+- Browser verified: welcome bubble displays correctly, chips render, clicking chip sends message and replaces welcome state
+- Files changed: `src/components/ChatWidget.tsx`
+- **Learnings for future iterations:**
+  - When refactoring a callback to accept optional parameters, wrap `onClick={handler}` as `onClick={() => handler()}` to prevent React from passing the SyntheticEvent as the first argument
+  - `SUGGESTED_QUESTIONS` as a module-level const is the simplest approach — easily editable, no data file needed for 3 items
+  - The `handleSubmit(overrideText?)` pattern avoids the stale-state problem: `setInputValue(text)` followed by immediate `handleSubmit()` would read the old `inputValue` since React batches state updates
+---
+
+## 2026-02-15 - US-013
+- Downloaded all-MiniLM-L6-v2 model files to `public/models/Xenova/all-MiniLM-L6-v2/`:
+  - `config.json`, `tokenizer.json`, `tokenizer_config.json`, `onnx/model_quantized.onnx` (~22MB)
+- Updated `src/lib/embedding-model.ts`:
+  - `env.localModelPath = '/models/'` — Vite serves `public/` at root
+  - `env.allowRemoteModels = false` — prevents any HF CDN fallback
+  - `env.useBrowserCache = false` — prevents stale Cache API entries from interfering
+- Updated `scripts/generate-embeddings.ts`:
+  - `env.localModelPath = resolve(import.meta.dirname, '..', 'public', 'models')` — absolute path for Node.js
+  - `env.allowRemoteModels = false`
+- Model files committed as static assets (not in .gitignore)
+- Browser verified: all 4 model files fetched from `localhost:5173/models/` with 200 OK, zero `huggingface.co` requests
+- Semantic search verified working: "data analysis" returns multi-category results (Core Skills, Active Projects, Achievements)
+- Build script (`npm run generate-embeddings`) still works with local model files
+- Typecheck passes (0 errors), lint passes (0 new errors/warnings)
+- Files changed: `src/lib/embedding-model.ts`, `scripts/generate-embeddings.ts`, `public/models/Xenova/all-MiniLM-L6-v2/` (new directory with 4 files)
+- **Learnings for future iterations:**
+  - `@xenova/transformers` env configuration: `env.localModelPath` sets the base path, `env.allowRemoteModels = false` prevents CDN fallback, `env.useBrowserCache = false` bypasses Browser Cache API
+  - The library constructs paths as `{localModelPath}/{modelId}/{filename}` — so `/models/` + `Xenova/all-MiniLM-L6-v2` + `/onnx/model_quantized.onnx`
+  - Browser Cache API can retain stale entries from previous HF CDN loads — setting `useBrowserCache = false` forces fresh fetches from the configured local path
+  - For Node.js scripts, use an absolute filesystem path for `localModelPath` (not a URL)
+  - The quantized ONNX model (`model_quantized.onnx`) is ~22MB — acceptable for a static asset since it's cached after first load
+---
+
+## 2026-02-15 - US-014
+- Reviewed and tightened system prompt in `src/lib/gemini.ts` for Gemini 3 Flash Preview
+- Prefixed each CV entry with its item ID (`[exp-nhs-nwicb] ...`) so the model can directly map entries to IDs for the ITEMS suffix
+- Replaced numbered rules with cleaner bullet-point format, added rule against fabricating URLs/contacts
+- Provided concrete example in ITEMS instruction (`[ITEMS: exp-nhs-nwicb, skill-python]`) instead of generic placeholders
+- Verified model constant (`GEMINI_MODEL = 'gemini-3-flash-preview'`), display name, API URL, and header indicator were already in place from previous iteration
+- Confirmed `gemini-3-flash-preview` is the correct model ID via Google AI docs
+- Typecheck (0 errors), lint (0 new warnings), and production build all pass
+- Files changed: `src/lib/gemini.ts`
+- **Learnings for future iterations:**
+  - Prefixing CV data with `[item-id]` in the system prompt makes ID references more reliable — model can directly see and copy IDs rather than inferring from patterns
+  - Concrete examples in format instructions (e.g., `[ITEMS: exp-nhs-nwicb, skill-python]`) are more reliable than generic placeholders (`[ITEMS: id1, id2]`)
+  - The `GEMINI_MODEL` and `GEMINI_DISPLAY_NAME` constants in `gemini.ts` are already exported and used by `ChatWidget.tsx` — single source of truth for model identity
+---
+
+## 2026-02-16 - US-014
+- Renamed `src/lib/gemini.ts` → `src/lib/llm.ts` via `git mv`
+- Rewrote `llm.ts` for OpenRouter API (OpenAI-compatible format):
+  - API endpoint: `https://openrouter.ai/api/v1/chat/completions`
+  - Model: `z-ai/glm-5` (exported as `LLM_MODEL`)
+  - Display name: `GLM-5` (exported as `LLM_DISPLAY_NAME`)
+  - Auth: `Authorization: Bearer` header using `VITE_OPEN_ROUTER_API_KEY` env var
+  - Added `HTTP-Referer` and `X-Title` headers per OpenRouter docs
+  - System prompt sent as `role: 'system'` message (first in messages array) instead of Gemini's `system_instruction` field
+  - SSE streaming parses `choices[0].delta.content` instead of Gemini's `candidates[0].content.parts[0].text`
+  - No `'model'` role mapping needed — OpenRouter uses `'assistant'` directly
+  - Request body uses `max_tokens` (OpenAI format) instead of `maxOutputTokens` (Gemini format)
+- Renamed `isGeminiAvailable()` → `isLLMAvailable()`, updated all call sites in `ChatWidget.tsx`
+- Updated all imports: `ChatWidget.tsx` now imports from `@/lib/llm` instead of `@/lib/gemini`
+- Renamed `GEMINI_DISPLAY_NAME` → `LLM_DISPLAY_NAME` and updated ChatWidget header display
+- `buildSystemPrompt()` now exported (was private) for use by benchmark script in US-015
+- Fixed merge conflict in `Ralph/prd.json` (resolved to keep OpenRouter migration stories US-014–US-019)
+- `parseItemIds()` and `stripItemsSuffix()` unchanged — response format spec is the same
+- Typecheck (0 errors), lint (0 new errors), production build all pass
+- Files changed: `src/lib/gemini.ts` → `src/lib/llm.ts` (renamed + rewritten), `src/components/ChatWidget.tsx`, `Ralph/prd.json`
+- **Learnings for future iterations:**
+  - OpenRouter uses OpenAI-compatible format: `messages` array with `role: 'system'|'user'|'assistant'`, `choices[0].delta.content` for streaming
+  - Gemini's `system_instruction` field → OpenRouter's first message with `role: 'system'`
+  - Gemini's `'model'` role → OpenRouter's `'assistant'` role (no mapping needed since ChatMessage already uses 'assistant')
+  - OpenRouter requires `HTTP-Referer` and `X-Title` headers — use `window.location.origin` for referer
+  - `VITE_OPEN_ROUTER_API_KEY` replaces `VITE_GEMINI_API_KEY` — update `.env` file accordingly
+  - `buildSystemPrompt()` is now exported from `llm.ts` — benchmark script (US-015) can import it directly instead of duplicating the logic
+  - The benchmark script (`scripts/benchmark.ts`) still uses the old Gemini API — needs separate migration in US-015
+---
+
+## 2026-02-16 - US-015
+- Migrated `scripts/benchmark.ts` from Gemini API to OpenRouter API
+- Replaced `GEMINI_MODEL` / `GEMINI_API_BASE` with `LLM_MODEL = 'z-ai/glm-5'` and `OPENROUTER_API_URL`
+- Updated `getApiKey()` to read `VITE_OPEN_ROUTER_API_KEY` from `.env`
+- Renamed `callGemini()` → `callLLM()` with OpenRouter request format:
+  - OpenAI-compatible messages array with `role: 'system'` for system prompt
+  - Auth via `Authorization: Bearer` header (not URL param)
+  - Added `HTTP-Referer` and `X-Title` headers per OpenRouter docs
+  - Response parsing: `choices[0].message.content` (non-streaming format)
+  - `max_tokens` (OpenAI format) instead of `maxOutputTokens` (Gemini format)
+- Updated `buildSystemPrompt()` to match production `llm.ts` format: item ID prefixes (`[item-id]`), same rules and instructions
+- Scoring calls also use OpenRouter via `callLLM()` (same model)
+- Rate limit retry logic kept same structure, updated error message text for OpenRouter
+- Model name in results output updated to `z-ai/glm-5`
+- Verified end-to-end: `npm run benchmark` runs all 10 questions, scores them, saves results to `scripts/benchmark-results/iteration-0.json`
+- Typecheck passes (0 errors), lint passes (0 new errors/warnings)
+- Files changed: `scripts/benchmark.ts`
+- **Learnings for future iterations:**
+  - Cannot import `buildSystemPrompt` from `src/lib/llm.ts` into Node scripts — `llm.ts` uses `import.meta.env` (Vite-only) and `window.location` (browser-only). Keep a mirrored copy in the benchmark script
+  - OpenRouter non-streaming response format: `{ choices: [{ message: { content: '...' } }] }` — different from streaming which uses `delta.content`
+  - For Node.js scripts, use a static URL for `HTTP-Referer` header (e.g., `'https://andycharlwood.co.uk'`) since `window.location` isn't available
+  - The benchmark script's `buildSystemPrompt()` should be kept in sync with `llm.ts` manually — if one changes, update the other (US-016/US-017 will modify the production prompt)
+---
+
+## 2026-02-16 - US-016
+- Rewrote `buildSystemPrompt()` in `src/lib/llm.ts` with full CV context from `References/CV_v4.md`
+- Replaced `buildEmbeddingTexts()` approach (one-paragraph-per-item) with structured CV format:
+  - Profile section with professional summary
+  - Career History with full achievement bullets per role, clinical specialties, methodology details
+  - Projects with tech stack and outcomes
+  - Education with grades, subjects, research topics, classifications
+  - Skills in compact format with years and proficiency
+- NHS employment (May 2022+, all at Norfolk & Waveney ICB) explicitly distinguished from private sector (Tesco PLC)
+- Clinical specialties listed under High-Cost Drugs role: rheumatology, ophthalmology (wet AMD, DMO, RVO), dermatology, gastroenterology, neurology, migraine
+- dm+d integration details, switching algorithm methodology, tirzepatide commissioning context all included
+- Mary Seacole Programme: 2018, 78%, NHS Leadership Academy
+- A-Levels: Mathematics A*, Chemistry B, Politics C — Highworth Grammar School 2009–2011
+- System prompt is 7,982 bytes (under 8KB limit)
+- Removed `buildEmbeddingTexts` import from llm.ts (no longer needed)
+- Mirrored identical prompt in `scripts/benchmark.ts` (with comment noting manual sync requirement)
+- Removed `buildEmbeddingTexts` import from benchmark.ts
+- Typecheck (0 errors), lint (0 errors), production build all pass
+- Files changed: `src/lib/llm.ts`, `scripts/benchmark.ts`
+- **Learnings for future iterations:**
+  - The structured CV format (markdown headers + bullets per role) is more effective for LLM Q&A than one-paragraph-per-palette-item — LLMs parse structured markdown better
+  - Item IDs are embedded in section headers (e.g., `### [exp-deputy-head-2024]`) rather than as line prefixes — cleaner format that still allows the model to reference IDs
+  - System prompt no longer depends on `buildEmbeddingTexts()` — the CV context is hardcoded. This means prompt content and embedding texts can diverge (prompt is optimised for Q&A, embeddings for semantic search)
+  - When the prompt is close to the 8KB limit, trim verbose connecting phrases and redundant qualifiers first — the specific facts and numbers are what matter for accuracy
+---
+
+## 2026-02-16 - US-017
+- Improved Response Rules in system prompt (`src/lib/llm.ts`) with numbered, clearer behavioral instructions:
+  1. Explicit "I don't have that information" phrasing for missing data
+  2. Stronger employer distinction instruction with "Never conflate the two"
+  3. Aggregation instruction broadened to include "projects" alongside tools/skills/achievements
+  4. Explicit prohibition on "approximately" and "around" when exact figures exist
+  5. Adaptive length instruction: thorough for list/detail questions, concise for simple ones
+- Lowered temperature from 0.7 to 0.4 for more consistent factual responses
+- Increased max_tokens from 512 to 800 to avoid truncating detailed answers
+- Preserved [ITEMS: ...] suffix instruction unchanged
+- Mirrored identical changes in `scripts/benchmark.ts` (prompt, temperature defaults, max_tokens defaults)
+- Typecheck (0 errors), lint (0 errors), production build passes
+- Files changed: `src/lib/llm.ts`, `scripts/benchmark.ts`
+- **Learnings for future iterations:**
+  - Numbered rules in system prompts tend to be followed more reliably by LLMs than bullet points
+  - Temperature 0.4 is a good balance for factual Q&A — low enough for consistency, high enough to avoid repetitive phrasing
+  - The benchmark script's `callLLM()` uses default params `temperature = 0.4, maxTokens = 800` — these match production. The scoring call overrides temperature to 0 for deterministic scoring
+  - The adaptive length rule ("thorough for detailed questions, concise for simple ones") replaces the fixed "2-4 sentences" rule — this should improve scores on questions requiring enumeration
+---
+
+## 2026-02-16 - US-018
+- Enriched `buildEmbeddingTexts()` in `src/lib/search.ts` with significantly richer text per item:
+  - **Consultations**: Added employer classification (NHS vs private sector), `plan` outcomes alongside `examination` bullets, and role-specific context (clinical specialties for high-cost drugs, dm+d/tirzepatide for deputy head, switching algorithm detail for interim head, LPC/community pharmacy for Tesco)
+  - **Skills**: Added `skillContextMap` with per-skill practical application context — links each skill to specific roles, projects, and outcomes (e.g., Python → switching algorithm, CD monitoring; Power BI → PharMetrics dashboard; NICE TA → clinical specialties covered)
+  - **Projects**: Added `projectContextMap` with role context and cross-references (e.g., CD monitoring links to controlled drugs skill, Blueteq links to clinical specialties)
+  - **Achievements**: Added full KPI story period alongside existing context/role/outcomes
+  - **Education**: Added `researchGrade` to embedding text (75.1% Distinction for MPharm research)
+- Regenerated `src/data/embeddings.json` — 42 items × 384-d vectors (file now ~453KB, 74% rewritten due to new vector values)
+- Typecheck (0 errors), lint (0 new warnings), production build all pass
+- Files changed: `src/lib/search.ts`, `src/data/embeddings.json`, `Ralph/prd.json`
+- **Learnings for future iterations:**
+  - Enriching embedding texts with role context and cross-references dramatically improves semantic search quality — queries like "clinical specialties" now match the high-cost drugs role AND the NICE TA skill AND clinical pathways skill, not just items with "clinical" in the title
+  - The `skillContextMap` and `projectContextMap` approach keeps enrichment data co-located with the embedding function rather than spreading it across data files — easier to maintain and update
+  - Embedding text should include employer classification (NHS vs private sector) since benchmark questions specifically test this distinction
+  - Cross-referencing between items (e.g., "Related to controlled drugs skill") helps semantic search surface related items even when the query doesn't exactly match an item's primary topic
+---
+
+## 2026-02-16 - US-019
+- Ran benchmark iteration 1 after structural prompt improvements → 18/20 score but Q10 had a zero due to ambiguous expected answer
+- **Structural prompt improvements applied to both `src/lib/llm.ts` and `scripts/benchmark.ts`:**
+  - Added **Employment Timeline (IMPORTANT)** section explicitly separating NHS (~4 years, May 2022+) from private sector (Tesco PLC)
+  - Added GPhC registration clarification ("professional licence, NOT an employer or NHS role")
+  - Labeled Tesco role bullets as "Leadership training:" and "Leadership development:" for discoverability
+  - Strengthened Rule 2 to include GPhC distinction
+  - Trimmed verbose text to keep prompt under 8KB (final: 8,007 bytes)
+- Fixed Q10 benchmark config: expected answer was ambiguous about whether Andy "completed" the Tesco induction (he created it) and "has" NVQ3 (he supervised others through it). Updated to accurately reflect CV data
+- **Iteration 2 results: 19/20 — PASSED** (threshold: 18/20, no zeros)
+  - Q01: 2/2 (was 0 — NHS vs Tesco now correctly distinguished)
+  - Q02: 2/2 (was 1 — tirzepatide details now fully covered)
+  - Q08: 2/2 (was 1 — dm+d details now fully covered)
+  - Q09: 1/2 (missing "variance analysis" — not a critical gap)
+  - Q10: 2/2 (was 0/1 — leadership training now fully covered with corrected expected answer)
+- Tested 5 general questions: "Tell me about Andy", "What does Andy do?", "How can I contact Andy?", "What is this website?", "What are Andy's strongest skills?" — all produce sensible, accurate responses. Contact question correctly responds "I don't have that information"
+- Results saved to `scripts/benchmark-results/iteration-2.json`
+- Files changed: `src/lib/llm.ts`, `scripts/benchmark.ts`, `scripts/benchmark-config.json`, `Ralph/prd.json`, `Ralph/progress.txt`
+- **Learnings for future iterations:**
+  - The Employment Timeline section at the top of the system prompt is critical for employer classification — without it, the model conflated GPhC registration with NHS employment
+  - Labeling achievements with their category (e.g., "Leadership training:") helps the model surface them under relevant queries
+  - When a benchmark question's expected answer is ambiguous, fix the expected answer to match the source CV data rather than tweaking the prompt to match a potentially incorrect expectation
+  - System prompt size limit of 8KB requires careful compression — trim verbose connecting words and redundant qualifiers, not facts
+  - The `z-ai/glm-5` model responds well to explicit structural cues like "(IMPORTANT)" headers and bold emphasis in the system prompt
+---

ralph.yml

@@ -0,0 +1,34 @@
+# Ralph Orchestrator Configuration
+# Generated by: ralph init --backend codex
+# Docs: https://github.com/mikeyobrien/ralph-orchestrator
+
+cli:
+  backend: "codex"
+
+event_loop:
+  prompt_file: "PROMPT.md"
+  completion_promise: "LOOP_COMPLETE"
+  max_iterations: 100
+  # max_runtime_seconds: 14400    # 4 hours max
+
+# ─────────────────────────────────────────────────────────────────────────────
+# Additional Configuration (uncomment to customize)
+# ─────────────────────────────────────────────────────────────────────────────
+
+# core:
+#   scratchpad: ".ralph/agent/scratchpad.md"
+#   specs_dir: ".ralph/specs/"
+
+# Custom hats for multi-agent workflows:
+# hats:
+#   builder:
+#     name: "Builder"
+#     triggers: ["build.task"]
+#     publishes: ["build.done", "build.blocked"]
+#
+#   reviewer:
+#     name: "Reviewer"
+#     triggers: ["review.request"]
+#     publishes: ["review.approved", "review.changes_requested"]
+
+# Create PROMPT.md with your task, then run: ralph run

tasks/prd-career-constellation-overhaul.md

@@ -0,0 +1,265 @@
+# PRD: Career Constellation — Clinical Pathway Overhaul
+
+## Introduction
+
+The CareerConstellation D3 force-directed graph sits alongside the work experience timeline in the "Patient Pathway" section. It currently looks prototype-quality: the timeline runs in the wrong direction, the chart doesn't fill the available height, node styling is basic, and the visual language doesn't match the refined GP clinical system aesthetic used across the rest of the portfolio.
+
+This PRD covers a comprehensive visual and structural overhaul to transform the graph into a polished, clinical-style patient pathway diagram that complements the adjacent work experience timeline — with synchronised year positions, bidirectional hover highlighting, and a refined design language matching the rest of the dashboard.
+
+**Implementation note:** All user stories involving D3 rendering changes should use the `d3-viz` skill.
+
+## Goals
+
+- Reverse the timeline to top = latest (2025), bottom = earliest (2017) so it visually syncs with the reverse-chronological work experience cards beside it
+- Dynamically match the graph's height to the work experience column so both columns align
+- Achieve visual parity with the rest of the dashboard — clean, clinical, premium, not prototype-looking
+- Implement bidirectional highlighting between the work experience timeline cards and the constellation graph
+- Create a clear visual hierarchy where skill nodes stay muted until contextually relevant (hover/click)
+
+## User Stories
+
+### US-001: Reverse timeline direction (top = most recent)
+
+**Description:** As a visitor, I want the graph's vertical timeline to run top-to-bottom from 2025→2017 so that the year positions visually align with the reverse-chronological work experience cards in the adjacent column.
+
+**Acceptance Criteria:**
+- [ ] `yScale` domain is reversed: `[maxYear, minYear]` maps to `[topPadding, height - bottomPadding]`
+- [ ] Role nodes appear at their correct year positions with 2025 near the top and 2017 near the bottom
+- [ ] Year labels along the timeline axis read top-to-bottom: 2025, 2024, 2023, ... 2017
+- [ ] Skill nodes cluster around their linked roles at the correct vertical positions
+- [ ] The timeline vertical line, year dots, and horizontal guide lines all reflect the reversed scale
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser using dev server
+
+### US-002: Dynamic height matching with work experience column
+
+**Description:** As a visitor, I want the constellation graph to fill the same vertical space as the work experience column so both columns appear balanced and the graph uses its full available height.
+
+**Acceptance Criteria:**
+- [ ] Remove fixed `DESKTOP_HEIGHT`, `TABLET_HEIGHT`, `MOBILE_HEIGHT` constants
+- [ ] The graph container measures the rendered height of the adjacent `.chronology-stream` element and uses that as its own height
+- [ ] Use a `ResizeObserver` on the chronology column to update the graph height when cards expand/collapse
+- [ ] Set a sensible minimum height (e.g. 400px) so the graph doesn't collapse on short content
+- [ ] On mobile (single-column layout), the graph uses a reasonable standalone height (e.g. 360px) since the columns stack
+- [ ] The `viewBox` and all D3 scales update correctly when height changes
+- [ ] Typecheck passes
+- [ ] Verify in browser — expand/collapse work experience cards and confirm the graph height adjusts
+
+### US-003: Clinical pathway visual language — background and structure
+
+**Description:** As a visitor, I want the graph to look like a clinical patient pathway diagram — clean, precise, and institutional — matching the GP system dashboard aesthetic.
+
+**Acceptance Criteria:**
+- [ ] Replace the radial gradient background with a clean white (`var(--surface)`) or very subtle warm tint matching `var(--bg-dashboard)`
+- [ ] Add a subtle 1px border matching `var(--border-light)` and `border-radius: var(--radius-sm)` consistent with other dashboard cards
+- [ ] Timeline axis styled as a refined vertical rule: 1px solid `var(--border)` colour, not the current thick teal line
+- [ ] Year markers are small ticks extending from the timeline, not floating dots — styled like clinical chart gridlines
+- [ ] Year labels use `font-family: var(--font-geist-mono)`, `font-size: 10px`, colour `var(--text-tertiary)` — matching dashboard data labels
+- [ ] Horizontal guide lines are very subtle (0.3 opacity, dashed or dotted) — they guide the eye without dominating
+- [ ] Remove the existing legend box (it takes up valuable space and will be replaced in US-007)
+- [ ] All colours use CSS custom properties from the design system (`var(--accent)`, `var(--success)`, `var(--amber)`, etc.)
+- [ ] Typecheck passes
+- [ ] Verify in browser — the graph should feel like it belongs on the same page as the other tiles
+
+### US-004: Role node redesign — clinical record anchors
+
+**Description:** As a visitor, I want role nodes to look like refined clinical record entries rather than basic coloured circles, clearly anchored to their timeline position.
+
+**Acceptance Criteria:**
+- [ ] Role nodes rendered as rounded rectangles (pill shapes) rather than circles — wider to accommodate text, roughly 90-110px wide x 32-36px tall
+- [ ] Each role node displays the `shortLabel` text centred inside, using `font-family: var(--font-ui)`, weight 600, size 11px
+- [ ] Role node fill uses the `orgColor` from data at reduced opacity (e.g. 0.12) with a 1px border of the same colour at higher opacity (0.4), and text in the `orgColor` at full strength — creating a subtle badge effect
+- [ ] A thin connector line links each role node horizontally back to the timeline axis at its year position — like a clinical event marker
+- [ ] Role nodes have a subtle hover state: border opacity increases, shadow appears (`var(--shadow-sm)`)
+- [ ] Active/pinned role node: border becomes solid at full `orgColor`, subtle inset glow or stronger shadow
+- [ ] Role nodes are positioned to the right of the timeline axis with consistent horizontal offset
+- [ ] Typecheck passes
+- [ ] Verify in browser — role nodes should look like labelled clinical event markers
+
+### US-005: Skill node redesign — muted by default, revealed on interaction
+
+**Description:** As a visitor, I want skill nodes to be visually subdued by default, becoming prominent only when a connected role or skill is hovered or clicked — creating a clean resting state and a meaningful highlighted state.
+
+**Acceptance Criteria:**
+- [ ] Default (resting) state for skill nodes: small circles (radius 6-8px), fill opacity 0.25, no visible label
+- [ ] Skill node fill colour determined by domain: technical = `var(--accent)`, clinical = `var(--success)`, leadership = `var(--amber)`
+- [ ] When a connected role is hovered/pinned: connected skill nodes transition to radius 10-12px, fill opacity 0.85, and their labels fade in (opacity 0 → 1, 200ms ease-out)
+- [ ] Skill labels use `font-family: var(--font-geist-mono)`, size 10px, colour `var(--text-secondary)`
+- [ ] When a skill node itself is hovered: that skill and all its connected roles highlight, with the skill growing to full size and showing its label
+- [ ] Link lines from roles to skills: default state is very subtle (opacity 0.08-0.12); highlighted state is 0.5-0.7 with domain colour
+- [ ] Unconnected nodes (not part of the active highlight group) reduce to opacity 0.08 — nearly invisible
+- [ ] Transitions between states are smooth (150-200ms) and respect `prefers-reduced-motion`
+- [ ] Typecheck passes
+- [ ] Verify in browser — the graph should feel clean and quiet at rest, informative on interaction
+
+### US-006: Bidirectional hover highlighting with work experience cards
+
+**Description:** As a visitor, I want to hover over a work experience card in the timeline and see the corresponding role and its skills light up in the graph, and vice versa — creating a clear visual link between the two columns.
+
+**Acceptance Criteria:**
+- [ ] Hovering a `RoleItem` in `WorkExperienceSubsection` calls `onNodeHighlight(consultation.id)` (already partially implemented)
+- [ ] The `CareerConstellation` component receives `highlightedNodeId` and applies the highlight logic from US-005
+- [ ] Hovering a role node in the graph triggers a callback that highlights the corresponding work experience card in the timeline (new: requires a reverse callback)
+- [ ] Add a new prop `onNodeHover?: (id: string | null) => void` to `CareerConstellation` — fires on mouseenter/mouseleave of role nodes
+- [ ] `DashboardLayout` passes this callback and uses it to set a `highlightedRoleId` state
+- [ ] `WorkExperienceSubsection` receives `highlightedRoleId` and applies a subtle highlight style to the matching card (e.g. border colour change to `var(--accent-border)`, light background tint)
+- [ ] `LastConsultationSubsection` also participates in the highlight system for the most recent role
+- [ ] Highlight clears when mouse leaves both the card and the graph node
+- [ ] On touch devices, tap-to-pin behaviour works as before — tapping a role pins the highlight in both the graph and the timeline
+- [ ] Typecheck passes
+- [ ] Verify in browser — hover over work experience cards and confirm the graph highlights; hover graph nodes and confirm the timeline cards highlight
+
+### US-007: Compact domain legend and graph header
+
+**Description:** As a visitor, I want a small, unobtrusive legend that explains the domain colour coding without taking up significant graph space.
+
+**Acceptance Criteria:**
+- [ ] Remove the existing boxed legend from inside the SVG
+- [ ] Add a compact inline legend below (or above) the SVG container — rendered as React HTML, not SVG
+- [ ] Legend shows three small coloured dots with labels: "Technical", "Clinical", "Leadership" — using the domain colours from the design system
+- [ ] Legend text uses `font-family: var(--font-geist-mono)`, size 10px, colour `var(--text-tertiary)`
+- [ ] Legend is horizontally laid out with subtle separators, taking minimal vertical space (single line, ~20px tall)
+- [ ] Include a small "Hover to explore connections" hint text in the legend row, matching the tertiary text style
+- [ ] Typecheck passes
+- [ ] Verify in browser
+
+### US-008: Link line refinement — clinical pathway connections
+
+**Description:** As a visitor, I want the connection lines between roles and skills to look like refined clinical pathway links rather than basic straight lines.
+
+**Acceptance Criteria:**
+- [ ] Replace straight `<line>` elements with curved `<path>` elements using D3 curve generators (e.g. `d3.curveBasis` or `d3.curveBundle`)
+- [ ] Default link styling: 1px stroke, colour `var(--border-light)`, opacity 0.12 — barely visible at rest
+- [ ] Highlighted link styling: 1.5-2px stroke, domain colour of the skill end, opacity 0.5-0.7
+- [ ] Link `strength` value from data influences the highlighted stroke opacity (stronger connections more visible)
+- [ ] Links animate smoothly between default and highlighted states (150ms transition)
+- [ ] Respect `prefers-reduced-motion` — skip transitions, jump to final state
+- [ ] Typecheck passes
+- [ ] Verify in browser — links should be nearly invisible at rest and clearly trace pathways on hover
+
+### US-009: Force simulation tuning for clinical layout
+
+**Description:** As a developer, I want the D3 force simulation tuned so that role nodes stay firmly anchored to their timeline positions while skill nodes distribute cleanly in the available space to the right.
+
+**Acceptance Criteria:**
+- [ ] Role nodes are effectively fixed to their timeline Y position (very high `forceY` strength, e.g. 0.95-1.0) and a consistent X position offset from the timeline
+- [ ] Skill nodes distribute in the space to the right of the role nodes, clustered near their connected roles but with enough separation to avoid overlap
+- [ ] Increase collision radius slightly to prevent label overlap when skills are revealed on hover
+- [ ] Simulation settles quickly — `alphaDecay` tuned so the graph stabilises within 1-2 seconds (or immediately for `prefers-reduced-motion`)
+- [ ] Boundary clamping keeps all nodes within the SVG viewport with adequate padding (role labels don't clip, skill labels don't overflow)
+- [ ] On height changes (from US-002), the simulation re-initialises smoothly without jarring jumps
+- [ ] Typecheck passes
+- [ ] Verify in browser — nodes should feel organised and intentional, not randomly scattered
+
+### US-010: Content audit — verify role descriptions against CV
+
+**Description:** As the portfolio owner, I want to ensure all role titles, organisations, dates, and achievement bullets in the work experience data are accurate and up-to-date against the source CV.
+
+**Acceptance Criteria:**
+- [ ] Cross-reference `src/data/consultations.ts` against `References/CV_v4.md` and `References/Andy_Charlwood_CV_ATS_Optimised.pdf`
+- [ ] Verify all role titles match exactly (e.g. "Interim Head, Population Health & Data Analysis" not abbreviated incorrectly)
+- [ ] Verify all organisation names match (e.g. "NHS Norfolk & Waveney ICB" consistently)
+- [ ] Verify all date ranges are correct (start/end dates for each role)
+- [ ] Verify achievement bullets (`examination` arrays) are accurate — numbers, percentages, and claims match the CV source
+- [ ] Verify `constellation.ts` role node data (labels, shortLabels, orgColors, years) is consistent with consultations data
+- [ ] Flag and fix any discrepancies found
+- [ ] Document any intentional differences (e.g. shortened bullet text for space)
+
+### US-011: Accessibility hardening
+
+**Description:** As a visitor using assistive technology, I want the constellation graph to be fully accessible with keyboard navigation and screen reader support.
+
+**Acceptance Criteria:**
+- [ ] The hidden accessibility buttons (already present) have `pointerEvents: 'auto'` so they are actually focusable/clickable (currently set to `'none'`)
+- [ ] Tab order follows a logical sequence: role nodes in reverse-chronological order, then skill nodes grouped by domain
+- [ ] Focus ring styling is visible and uses the design system accent colour with sufficient contrast
+- [ ] Screen reader description (`srDescription`) is updated to reflect the reversed timeline direction
+- [ ] `aria-label` on the SVG is updated to mention the clinical pathway metaphor
+- [ ] All interactive states (hover highlight, pin, expand) are achievable via keyboard
+- [ ] `prefers-reduced-motion` is respected throughout — all animations skip to final state
+- [ ] Typecheck passes
+- [ ] Test with keyboard navigation — Tab through all nodes, Enter to activate
+
+### US-012: Responsive behaviour — mobile and tablet
+
+**Description:** As a visitor on a smaller screen, I want the constellation graph to display appropriately when the columns stack vertically.
+
+**Acceptance Criteria:**
+- [ ] On mobile/tablet (single-column `.pathway-columns` layout), the graph renders at a reasonable fixed height (360-400px) since it no longer has a column to match
+- [ ] The graph simplifies slightly on mobile: role labels may use shorter text, skill node default radius decreases slightly
+- [ ] Touch interactions work correctly: tap to pin a node, tap elsewhere to unpin
+- [ ] The graph is not cropped or overflowing on narrow viewports (min-width handling)
+- [ ] The HTML legend from US-007 wraps gracefully on narrow screens
+- [ ] Typecheck passes
+- [ ] Verify in browser at mobile viewport widths (375px, 430px)
+
+## Functional Requirements
+
+- FR-1: The constellation graph's vertical axis must run top = 2025, bottom = 2017 (reverse chronological)
+- FR-2: The graph container must dynamically match the height of the adjacent chronology stream column
+- FR-3: All visual styling must use the project's CSS custom properties and design tokens
+- FR-4: Role nodes must be rendered as labelled rounded rectangles (pills) anchored to timeline positions
+- FR-5: Skill nodes must default to low opacity (0.25) with small radius, becoming prominent only on hover/pin
+- FR-6: Hovering a work experience card must highlight the corresponding graph node and its connections
+- FR-7: Hovering a graph role node must highlight the corresponding work experience card
+- FR-8: Connection lines must use curved paths, barely visible at rest, prominent when highlighted
+- FR-9: The force simulation must keep role nodes firmly at their timeline positions
+- FR-10: All role data must be verified against the source CV documents
+- FR-11: Keyboard navigation and screen reader support must be maintained and improved
+- FR-12: The graph must handle responsive breakpoints (desktop dual-column, mobile/tablet single-column)
+
+## Non-Goals
+
+- No animation of nodes entering the viewport (scroll-triggered animation)
+- No zoom/pan interaction on the graph
+- No tooltip popovers on nodes — interactions open the existing detail panel
+- No changes to the work experience card design itself (only adding highlight state)
+- No changes to the `LastConsultationSubsection` design (only adding highlight participation)
+- No changes to the boot, ECG, or login phases
+- No addition of new skills or roles beyond what's in the CV
+
+## Design Considerations
+
+### Visual Language
+The graph should feel like a **clinical patient pathway diagram** — the kind of clean, precise visualisation you'd see in a modern healthcare analytics dashboard. Think: straight connector lines with subtle curves, institutional colour palette, monospace data labels, status-indicator dots.
+
+### Colour Usage
+- Role nodes: Use `orgColor` from data at low opacity for fill, higher opacity for border and text — creating subtle badges
+- Skill nodes by domain: Technical `var(--accent)` / Clinical `var(--success)` / Leadership `var(--amber)`
+- All links and guides: Use `var(--border)` and `var(--border-light)` tokens
+- Highlighted state: Domain colour at moderate opacity, never garish
+
+### Typography in SVG
+- Role labels inside nodes: `var(--font-ui)`, weight 600, 11px
+- Skill labels below nodes: `var(--font-geist-mono)`, 10px
+- Year labels: `var(--font-geist-mono)`, 10px, `var(--text-tertiary)`
+- All SVG text should use the CSS custom property font stacks
+
+### Spacing
+- Timeline axis positioned ~100-140px from left edge
+- Role nodes offset ~80px right of the timeline axis
+- Generous top/bottom padding (40-50px) for breathing room
+- Skill nodes distributed in the remaining right-side space
+
+## Technical Considerations
+
+- **D3 version**: Use the existing `d3` import (already in `package.json`)
+- **Skill**: All D3 rendering work should use the `d3-viz` skill for implementation
+- **ResizeObserver**: For height synchronisation, observe the `.chronology-stream` element. The graph component needs a ref or selector to find it
+- **Simulation re-init**: When dimensions change, the simulation should restart with new scales but preserve node positions where possible to avoid jarring jumps
+- **Performance**: The simulation `tick` handler calls `setNodeButtonPositions` which triggers React re-renders. The current diffing logic should be preserved but tested under the new height-changing scenario
+- **Module-level code**: The current component has module-level `window.matchMedia` calls (`prefersReducedMotion`, `supportsCoarsePointer`) — these are fine for SPA but would break SSR. Not a concern for this project, but worth noting
+
+## Success Metrics
+
+- The constellation graph visually matches the quality level of other dashboard components (cards, sidebar, topbar)
+- Timeline year positions in the graph correspond to the vertical positions of the work experience cards in the adjacent column
+- A visitor can hover between the timeline and the graph and immediately understand the connection
+- The graph feels quiet and clean at rest, informative and precise on interaction
+- No accessibility regressions — keyboard navigation and screen reader support maintained or improved
+
+## Open Questions
+
+- Should the "Last Consultation" (most recent role) card participate in the bidirectional highlighting, or only the accordion items in `WorkExperienceSubsection`? **Answer: Yes, it should participate (noted in US-006)**
+- Should role nodes show the date range (e.g. "2024–Present") below the short label, or keep it minimal? Consider during implementation — add if space permits without clutter
+- Should skill nodes that appear in multiple roles show any visual indicator of "shared" status (e.g. a small count badge)? Defer to future iteration

tasks/prd-constellation-refinement.md

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+# PRD: Career Constellation Refinement
+
+## Introduction
+
+The career constellation graph needs visual and interaction refinements for better usability on large screens (1440p+), improved skill visibility, a more intuitive hover-based interaction model, and the addition of the full career + education timeline. The current implementation has overly aggressive opacity dimming on skills, too-small text at high resolutions, an unintuitive click-to-pin interaction, a constellation column that takes up too much horizontal space, and is missing early-career roles and education. Additionally, the work experience cards in the left column don't visually tie to their corresponding constellation nodes — they should use matching employer colours.
+
+## Goals
+
+- Improve readability of skill nodes and labels on large displays (1440p+)
+- Reduce the constellation column width to ~35% giving work experience ~65% of horizontal space
+- Replace click-to-highlight with hover-to-highlight on desktop, tap-to-highlight on mobile
+- Replace the slide-out detail sidebar on mobile with in-place accordion expansion
+- Scale all graph elements proportionally based on viewport width so the graph looks good from 1024px to 2560px+
+- Add the full timeline: Duty Pharmacy Manager, Pre-Reg Pharmacist, UEA MPharm, and Highworth A-Levels
+- Colour-match work experience cards to their constellation node employer colours
+- Establish a consistent employer/institution colour scheme across the entire UI
+
+## User Stories
+
+### US-001: Increase default skill node visibility
+**Description:** As a visitor, I want skill nodes to be more visible by default so I can see the full constellation without needing to interact.
+
+**Acceptance Criteria:**
+- [ ] Increase default skill circle `fill-opacity` from `0.2` to `0.35`
+- [ ] Increase active (highlighted) skill circle `fill-opacity` from `0.85` to `0.9`
+- [ ] Reduce the dimming of unconnected nodes when a role is highlighted — change from `opacity: 0.06` to `opacity: 0.15`
+- [ ] Skill labels should be partially visible by default at `opacity: 0.5` (currently hidden at `0`), fully visible at `opacity: 1` when highlighted
+- [ ] Link default `stroke-opacity` increased from `0.08` to `0.15` so the connection web is subtly visible
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: skills should be recognisable at a glance without hovering
+
+### US-002: Viewport-proportional scaling for large screens
+**Description:** As a visitor on a 1440p or larger display, I want the constellation elements to scale up so they aren't tiny relative to the screen.
+
+**Acceptance Criteria:**
+- [ ] Compute a scale factor based on viewport width: `scaleFactor = Math.max(1, Math.min(1.6, viewportWidth / 1440))` (1.0x at 1440px, up to 1.6x at 2560px+)
+- [ ] Apply scale factor to: `SKILL_RADIUS_DEFAULT` (7 -> up to ~11), `SKILL_RADIUS_ACTIVE` (11 -> up to ~18), `ROLE_WIDTH` (104 -> up to ~166), `ROLE_HEIGHT` (32 -> up to ~51)
+- [ ] Base skill label `font-size` raised to 11px minimum (from 10px), then scales proportionally (up to ~18px at max scale)
+- [ ] Base role label `font-size` raised to 12px minimum (from 11px), then scales proportionally (up to ~19px at max scale)
+- [ ] Base year label `font-size` raised to 11px minimum (from 10px), then scales proportionally
+- [ ] Scale padding, gaps, and force simulation parameters (charge, link distance, collision radius) proportionally
+- [ ] Mobile breakpoint (`< 640px`) is unaffected — scaling only applies at `>= 1024px`
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser at 1440px and 2560px widths: elements should be clearly legible and well-proportioned
+
+### US-003: Reduce constellation column width
+**Description:** As a visitor, I want more horizontal space for work experience content so the chronology stream is easier to read.
+
+**Acceptance Criteria:**
+- [ ] Change `.pathway-columns` desktop grid from `minmax(0, 1.15fr) minmax(0, 1.5fr)` to `minmax(0, 1.85fr) minmax(0, 1fr)` (approximately 65/35 split)
+- [ ] The constellation graph adapts to the narrower container without clipping or overflow
+- [ ] Force simulation parameters still produce a clean, non-overlapping layout in the narrower space
+- [ ] The timeline axis, role pills, and skill nodes remain fully visible
+- [ ] Sticky positioning of the graph column still works correctly
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: work experience column is visibly wider, graph is compact but readable
+
+### US-004: Hover-to-highlight interaction on desktop
+**Description:** As a desktop visitor, I want hovering over a role to highlight its connected skills, and hovering away to reset — without needing to click to toggle.
+
+**Acceptance Criteria:**
+- [ ] On desktop (fine pointer): hovering a role node highlights connected skills, shows their labels, and colorises links — same visual effect as current click behaviour
+- [ ] Moving the mouse away from a role resets to the default state (all nodes visible at baseline opacity per US-001)
+- [ ] Remove the click-to-pin toggle behaviour on desktop — clicking a role node should only trigger the detail action (e.g. expand accordion), not pin the highlight
+- [ ] Hovering a skill node still highlights that skill and its connected roles
+- [ ] The `pinnedNodeId` state is removed or only used for touch/keyboard
+- [ ] Keyboard navigation (Tab + Enter) still works: focus highlights the node, Enter opens details
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: hover on/off roles cycles highlight cleanly with no "stuck" states
+
+### US-005: Tap-to-highlight with accordion expansion on mobile
+**Description:** As a mobile visitor, I want tapping a role to highlight its skills and expand role details in-place, rather than opening a side panel.
+
+**Acceptance Criteria:**
+- [ ] On touch devices (coarse pointer): first tap on a role highlights its connected skills (same visual as desktop hover)
+- [ ] First tap also expands an accordion panel below the constellation graph showing the role's condensed details: title, organisation, date range, and top 3 key achievements
+- [ ] The accordion includes a "Show more" link/button to reveal the full set of achievements and details
+- [ ] Tapping a different role switches the highlight and accordion content (auto-collapses "show more" back to summary)
+- [ ] Tapping the same role again (or tapping elsewhere) collapses the accordion and resets highlights
+- [ ] The accordion uses the same expand/collapse animation pattern as other tiles (height-only, 200ms ease-out)
+- [ ] No slide-out sidebar panel on mobile — detail content lives in the accordion below the graph
+- [ ] Tapping a skill node highlights it and shows a brief skill tooltip or label, does not open a panel
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser at mobile viewport: tap role -> accordion expands, tap again -> collapses
+
+### US-006: Add Duty Pharmacy Manager role (Aug 2016 – Oct 2017)
+**Description:** As a visitor, I want to see the Duty Pharmacy Manager role in the constellation so the full career timeline is represented.
+
+**Acceptance Criteria:**
+- [ ] Add role node to `constellation.ts`: id `duty-pharmacy-manager-2016`, label "Duty Pharmacy Manager", shortLabel "Duty Pharm Mgr", organisation "Tesco PLC", startYear 2016, endYear 2017, orgColor `#E53935` (Tesco red)
+- [ ] Add role-skill mapping with these skill connections: `medicines-optimisation` (0.8), `data-analysis` (0.5), `excel` (0.6), `change-management` (0.5), `stakeholder-engagement` (0.4)
+- [ ] Add corresponding links to `constellationLinks` array
+- [ ] Add consultation entry to `consultations.ts` with title "Duty Pharmacy Manager", org "Tesco PLC", dates Aug 2016 – Oct 2017, location "Great Yarmouth, Norfolk", and key achievements from CV: service development leadership (NMS/asthma referrals), national clinical innovation (quality payments solution), clinical foundation building
+- [ ] The role appears on the timeline in correct chronological position (between Pre-Reg and Pharmacy Manager)
+- [ ] Screen reader description updates to include the new role
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: new role node appears on timeline, hover highlights correct skills
+
+### US-007: Add Pre-Registration Pharmacist role (Jul 2015 – Jul 2016)
+**Description:** As a visitor, I want to see the Pre-Registration Pharmacist role in the constellation as the earliest professional entry.
+
+**Acceptance Criteria:**
+- [ ] Add role node to `constellation.ts`: id `pre-reg-pharmacist-2015`, label "Pre-Registration Pharmacist", shortLabel "Pre-Reg", organisation "Paydens Pharmacy", startYear 2015, endYear 2016, orgColor `#66BB6A` (Paydens light green)
+- [ ] Add role-skill mapping with these skill connections: `medicines-optimisation` (0.7), `change-management` (0.4), `stakeholder-engagement` (0.3)
+- [ ] Add corresponding links to `constellationLinks` array
+- [ ] Add consultation entry to `consultations.ts` with title "Pre-Registration Pharmacist", org "Paydens Pharmacy", dates Jul 2015 – Jul 2016, location "Tunbridge Wells & Ashford, Kent", and key achievements from CV: clinical service expansion (PGDs for NRT, EHC, chlamydia), NMS audit improvement (under 10% to 50-60%), palliative care screening, operational learning
+- [ ] The role appears on the timeline below Duty Pharmacy Manager
+- [ ] Screen reader description updates to include the new role
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: new role node appears on timeline, hover highlights correct skills
+
+### US-008: Add University of East Anglia education node (2011 – 2015)
+**Description:** As a visitor, I want to see the MPharm degree on the timeline as the foundation of the career.
+
+**Acceptance Criteria:**
+- [ ] Add node to `constellation.ts`: id `uea-mpharm-2011`, type `role` (treated the same as work roles on the timeline), label "MPharm (Hons) 2:1", shortLabel "MPharm", organisation "University of East Anglia", startYear 2011, endYear 2015, orgColor `#7B2D8E` (UEA purple — distinct education colour)
+- [ ] Add role-skill mapping with foundational skill connections: `medicines-optimisation` (0.5), `data-analysis` (0.3)
+- [ ] Add corresponding links to `constellationLinks` array
+- [ ] Add consultation entry to `consultations.ts` with title "MPharm (Hons) 2:1", org "University of East Anglia", dates 2011 – 2015, location "Norwich", and key achievements: independent research project on drug delivery and cocrystals (75.1%, Distinction), 4th year OSCE 80%, President of UEA Pharmacy Society
+- [ ] The node appears on the timeline below Pre-Reg Pharmacist
+- [ ] Screen reader description updates to include the education entry
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: education node appears on timeline with distinct purple colour
+
+### US-009: Add Highworth Grammar School education node (2009 – 2011)
+**Description:** As a visitor, I want to see A-Levels on the timeline as the earliest entry, showing the complete timeline from 2009 to present.
+
+**Acceptance Criteria:**
+- [ ] Add node to `constellation.ts`: id `highworth-alevels-2009`, type `role`, label "A-Levels: Maths A*, Chem B", shortLabel "A-Levels", organisation "Highworth Grammar School", startYear 2009, endYear 2011, orgColor `#9C27B0` (lighter purple — education colour family, distinct shade from UEA)
+- [ ] Minimal skill connections: `data-analysis` (0.2) — reflects strong mathematics foundation
+- [ ] Add corresponding link to `constellationLinks` array
+- [ ] Add consultation entry to `consultations.ts` with title "A-Levels", org "Highworth Grammar School", dates 2009 – 2011, location "Ashford, Kent", and results: Mathematics A*, Chemistry B, Politics C
+- [ ] The node appears at the very bottom of the timeline as the earliest entry
+- [ ] Screen reader description updates to include the education entry
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: A-Levels node appears at bottom of timeline
+
+### US-010: Unify employer/institution colour scheme
+**Description:** As a visitor, I want each employer/institution to have a distinct, consistent colour so I can visually group entries by organisation.
+
+**Acceptance Criteria:**
+- [ ] NHS Norfolk & Waveney ICB roles use NHS blue `#005EB8` (already correct — Deputy Head, Interim Head, High-Cost Drugs)
+- [ ] Tesco PLC roles use Tesco red `#E53935` — update existing Pharmacy Manager node `orgColor` from `#00897B` to `#E53935` in both `constellation.ts` and `consultations.ts`
+- [ ] Paydens Pharmacy uses light green `#66BB6A` for Pre-Registration Pharmacist
+- [ ] University of East Anglia uses UEA purple `#7B2D8E`
+- [ ] Highworth Grammar School uses lighter purple `#9C27B0`
+- [ ] The domain legend below the graph is unchanged (Technical/Clinical/Leadership) — institution colours only appear on role/education pill nodes
+- [ ] All role pills remain legible with appropriate text contrast against the coloured fill/stroke
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: five distinct institution colour groups are immediately recognisable
+
+### US-011: Colour-match work experience cards to constellation nodes
+**Description:** As a visitor, I want the work experience cards in the left column to use matching colours from their constellation nodes, creating a visual link between the card list and the graph.
+
+**Acceptance Criteria:**
+- [ ] The dot indicator on each work experience card uses the consultation's `orgColor` instead of hardcoded `#0D6E6E`
+- [ ] The expanded card's left border uses the consultation's `orgColor` instead of `var(--accent)`
+- [ ] The bullet point dots in the expanded detail use the consultation's `orgColor` (at 0.5 opacity, matching current pattern) instead of `var(--accent)`
+- [ ] The coded entry tags use the consultation's `orgColor` for text colour and a lightened variant for background/border (same pattern as current teal, but using the org colour)
+- [ ] The "View full record" link uses the consultation's `orgColor` instead of `var(--accent)`
+- [ ] The highlight background when a card is highlighted from the graph uses a tinted version of `orgColor` at low opacity (e.g. `rgba(r,g,b,0.03)`) instead of hardcoded `rgba(10,128,128,0.03)`
+- [ ] The hover/expanded border colour uses a border variant of the `orgColor` instead of `var(--accent-border)`
+- [ ] The CardHeader dot for "WORK EXPERIENCE" section title remains teal (it's the section accent, not per-card)
+- [ ] All colour changes maintain WCAG AA contrast ratios for text legibility
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser: NHS roles show blue-tinted cards, Tesco roles show red-tinted cards, Paydens shows green, education shows purple
+
+### US-012: Re-tune force simulation for 8 timeline entries
+**Description:** As a developer, I need the force simulation to produce a clean layout with 8 entries (6 roles + 2 education) spanning 2009–2025, in the narrower column.
+
+**Acceptance Criteria:**
+- [ ] The y-scale range accommodates 8 entries (2009–2025) without excessive cramping
+- [ ] Timeline year labels show the full range from 2009 to 2025
+- [ ] Role/education nodes don't overlap each other on the timeline
+- [ ] Skill nodes distribute cleanly in the available space to the right of role pills
+- [ ] Adjust charge, collision, and link forces if needed to prevent overlapping with the additional nodes and narrower space
+- [ ] Links don't create an unreadable tangle — connections remain traceable
+- [ ] Education nodes at the bottom (2009–2015) have fewer skill connections so the lower portion isn't cluttered
+- [ ] The graph still works at mobile viewport widths with 8 entries
+- [ ] Typecheck passes (`npm run typecheck`)
+- [ ] Verify in browser at both desktop and mobile: all 8 entries visible, no overlaps, clean layout
+
+## Functional Requirements
+
+- FR-1: Skill node default opacity increased to 0.35 with labels at 0.5 opacity
+- FR-2: All graph element sizes (nodes, text, padding) scale proportionally with viewport width from 1024px to 2560px+
+- FR-3: Grid layout changes to ~65/35 split favouring the work experience column
+- FR-4: Desktop interaction model is hover-only (no click-to-pin for highlighting)
+- FR-5: Mobile interaction model is tap-to-highlight with accordion expansion for details (no sidebar panel)
+- FR-6: Four new timeline entries added: Duty Pharmacy Manager, Pre-Reg Pharmacist, UEA MPharm, Highworth A-Levels
+- FR-7: Force simulation produces a clean layout with 8 entries in a narrower column
+- FR-8: All accessibility features (keyboard navigation, screen reader descriptions, focus management) continue to work with 8 entries
+- FR-9: Institution colour scheme: NHS blue `#005EB8`, Tesco red `#E53935`, Paydens green `#66BB6A`, UEA purple `#7B2D8E`, Highworth purple `#9C27B0`
+- FR-10: Minimum font size of 11px for all text in the constellation graph on desktop
+- FR-11: Work experience cards use matching `orgColor` for dot, border, bullets, coded entries, and links
+- FR-12: Timeline spans 2009–2025 showing the complete career + education journey
+
+## Non-Goals
+
+- No changes to the boot sequence, ECG animation, or login screen
+- No new skill nodes — only new role/education nodes and links to existing skills
+- No changes to the domain legend below the graph (Technical/Clinical/Leadership categories)
+- No changes to the mobile stacked layout breakpoint (stays at 1024px)
+- No changes to skill detail panel or RepeatMedicationsSubsection
+
+## Design Considerations
+
+- The constellation is getting denser with 8 entries. The narrower column means less horizontal space for skill distribution. The force simulation tuning (US-012) is critical to prevent visual clutter.
+- Education entries at the bottom of the timeline (2009–2015) have deliberately few skill connections (2 for UEA, 1 for Highworth) to keep the lower portion clean and visually suggest the "before specialisation" phase.
+- The proportional scaling should feel natural — not just "zoomed in" but properly scaled with appropriate spacing.
+- The accordion on mobile (US-005) should match the existing tile expansion pattern — summary first (top 3 achievements), "show more" for full detail.
+- **Institution colours**: NHS blue, Tesco red, Paydens green, and purple shades for education. The purple family groups both education entries while using different shades to distinguish them. Role pill text uses the institution colour for both the label and the border/fill tint.
+- **Card colour matching**: The work experience cards should feel like they "belong to" their constellation node. The colour theming should be subtle — tinted backgrounds, coloured dots and borders — not overwhelming. Think: the current teal treatment but swapped per employer.
+
+## Technical Considerations
+
+- The scale factor computation should happen once per resize, not per render tick
+- Force simulation parameters (charge, link distance, collision radius) all need to scale with the viewport factor
+- The existing `chronologyRef` + `ResizeObserver` pattern for height matching should continue to work
+- The accordion component for mobile detail expansion can reuse existing expand/collapse patterns from `WorkExperienceSubsection`
+- Adding 4 entries increases total nodes from 25 to 29 and links from 46 to ~57
+- The `Consultation` type in `types/pmr.ts` may need updating if education entries need different fields (e.g. no `codedEntries`, different `examination` semantics) — or education entries can use the same shape with adapted content
+- For the card colour matching (US-011), a utility function to derive light/border variants from a hex colour would avoid hardcoding multiple CSS variable overrides per employer. Something like `hexToRgba(color, opacity)` for backgrounds and borders
+- The `orgColor` already exists on the `Consultation` type — it just isn't used in `WorkExperienceSubsection.tsx` yet
+
+## Success Metrics
+
+- All skill labels legible at 1440p without squinting
+- Hover-to-highlight feels instant and responsive (no stuck states)
+- Work experience column has noticeably more reading space
+- The full timeline (2009–present) is represented with education and career
+- Employer/institution colour coding is immediately recognisable across cards and graph
+- No visual overlaps or clipping at any supported viewport width
+
+## Open Questions
+
+- None — all decisions resolved.