# Progress Log

## Codebase Patterns
- Single self-contained HTML file. All CSS in a single `<style>` tag. All JS in a single `<script>` tag wrapped in an IIFE with 'use strict'.
- No frameworks, no build step. Only external dependency: Google Fonts via <link> tags.
- Boot sequence is shared: pure black #000 bg, Fira Code font, blinking green cursor (#00ff41, step-end animation), boot text typed line by line (~220ms apart), [OK] lines bright green bold, SYSTEM/USER/ROLE/LOCATION labels cyan #00e5ff, values bright green, other lines dim green #3a6b45.
- CV data source: Use the expanded CV_v4.md content. Key roles: Interim Head (May-Nov 2025), Deputy Head (Jul 2024-Present), High-Cost Drugs Pharmacist (May 2022-Jul 2024), Pharmacy Manager Tesco (Nov 2017-May 2022), Duty Pharmacy Manager Tesco (Aug 2016-Nov 2017).
- Use IntersectionObserver for scroll animations (not scroll event listeners).
- For smooth scroll on nav clicks: preventDefault, calculate offset, window.scrollTo with behavior:'smooth'.
- Output HTML file name convention: 4-vitals-monitor.html.
- ECG PQRST waveform shape: flat -> small P bump -> flat -> sharp Q dip -> tall R spike -> S dip -> flat -> gentle T wave -> flat.
- Use SVG paths with stroke-dasharray/stroke-dashoffset for line drawing animations.
- SVG circle skill gauges: circumference = 2*PI*r. stroke-dashoffset = circumference * (1 - level/100). rotate(-90deg) to start from top.
- Google Fonts: Plus Jakarta Sans, Inter Tight.
- Floating pill nav: NOT full width. max-width 600px, margin: 12px auto, border-radius 100px.
- ECG overlay: #ecg-overlay div at z-index 1001. SVG created dynamically with viewBox matching viewport dimensions.
- drawHeartbeat(svg, svgNS, vw, vh, cy, rHeight, color, duration, onComplete) — reusable PQRST waveform renderer. rHeight controls R peak amplitude. color and duration are per-beat customisable.
- finishECGPhase() handles cleanup: fades ECG lines, transitions boot bg to white, removes overlays, reveals CV. Task 3 will replace the call to this with expanded branching logic.
- requestAnimationFrame needed before setting CSS transitions on dynamically created SVG elements.
- SVG Z (closepath) draws back to the M (moveTo) point, NOT to the last subpath start. Don't use Z when tracing from an external origin to a rectangle — use explicit L commands instead.
- startBranching(svg, svgNS, vw, vh, cy, overlay, bootScreen) — creates branch paths from peak. finishECGPhase(overlay, bootScreen) — fades SVG, removes overlays from DOM, reveals CV content.
- Color interpolation for 3 beats: #00ff41 (green) → #00C9A7 (midpoint) → #00897B (teal). Match glow filter color to stroke color.

## Iteration Log

### Iteration 1 — Task 1: Build the boot screen foundation
- Created `4-vitals-monitor.html` with full boot screen implementation
- Boot sequence follows guardrail format exactly: CLINICAL TERMINAL v3.2.1, profile init, SYSTEM/USER/ROLE/LOCATION, modules, [OK] lines, READY
- Timing: 14 lines × 220ms = ~2860ms boot + 400ms pause + 800ms fade = ~4.06s total (within guardrail)
- Boot text fades to opacity:0, then boot screen is removed and CV content revealed
- Temporary: boot screen hides directly after fade (Task 2 will insert ECG phase between fade and reveal)
- CSS variables, all 3 Google Font families loaded, IIFE strict mode JS
- Learnings: setTimeout delay argument is evaluated at call-time, not in the closure callback, so using a cumulative var in forEach works correctly for staggered timing

### Iteration 2 — Task 2: Build the ECG flatline and first heartbeat
- Added ECG overlay phase between boot fade and CV reveal
- Flatline draws left-to-right (1000ms linear) using SVG stroke-dasharray/dashoffset
- First PQRST heartbeat (R peak 40px) draws over 600ms at viewport center
- drawHeartbeat() is a reusable function accepting: svg, svgNS, vw, vh, cy, rHeight, color, duration, onComplete callback — Task 3 calls this with different amplitudes
- finishECGPhase() is a temporary cleanup function that Task 3 will replace with expanded logic (2nd/3rd beats + branching)
- Timing: boot ~4s + ECG ~2.4s = ~6.4s total (within 8-9s guardrail)
- Learnings: SVG paths created via createElementNS need the SVG namespace 'http://www.w3.org/2000/svg'. requestAnimationFrame is needed before setting CSS transitions on dynamically created SVG elements to ensure the initial state is painted first.
- The ECG overlay z-index is 1001 (above boot screen at 1000) so the lines render on top of the black background

### Iteration 3 — Task 3: Build second and third heartbeats with overflow branching
- Replaced finishECGPhase() call after 1st beat with chained sequence: 1st→2nd→3rd→branching→reveal
- Second heartbeat: R peak 60px, stroke #00C9A7 (green-teal midpoint), bg lightens to #0A0A0A
- Third heartbeat: R peak 100px, stroke #00897B (full teal), bg lightens to #141414
- startBranching() creates 7 SVG branch paths from the 3rd R peak apex:
  - Branch 1: traces pill nav bar outline (rounded rect with Q curves for corners)
  - Branches 2-3: trace hero section left/right vertical edges
  - Branches 4-7: trace four vital sign card outlines (Q curve from peak to card top-left, then L lines around rectangle)
- Branches staggered by 50-150ms, 800ms draw with cubic-bezier easing
- Background transitions to white during branching (800ms ease-out)
- finishECGPhase() now accepts overlay/bootScreen params, removes elements from DOM (not just display:none)
- Glow filter on heartbeat paths dynamically matched to stroke color
- Total timing: ~8.5s (boot ~3.3s + flatline 1.05s + 3 beats ~2.55s + branching ~1.2s + fade 0.5s)
- Learnings: Don't use SVG Z (closepath) when tracing from an external origin to a rectangle — Z draws back to M point (the peak), not the rectangle's start corner. Instead, explicitly L back to the first rectangle corner.
- Learnings: When dynamically setting filter CSS on SVG elements, match the glow color to the stroke color for visual coherence.

### Iteration 4 — Task 4: Build final design skeleton with floating pill nav and typography
- Added floating pill nav bar: position: fixed; top: 16px; centered via left: 50% + translateX(-50%); max-width: 600px; border-radius: 999px; with subtle border and shadow
- Nav links use Inter Tight (--font-secondary) at 13px, muted color, with teal hover/active states
- Active nav link has a 4px teal dot below via ::after pseudo-element
- IntersectionObserver for active section tracking: threshold 0.3, rootMargin '-20% 0px -60% 0px'
- Smooth scroll: preventDefault on nav clicks, scrollTo with offset -70 and behavior: 'smooth'
- initNavTracking() called from finishECGPhase() after CV content is revealed (DOM must exist first)
- Main container: max-width 1000px, padding 0 32px, sections 80px vertical padding
- .section-heading utility class: 24px, 700 weight, heading color, margin-bottom 32px
- Responsive 768px: pill nav becomes full-width scrollable (overflow-x: auto, hidden scrollbar), main padding 20px
- Responsive 480px: nav links shrink to 11px/4px 8px padding, main padding 16px, section padding 48px
- All 6 sections added as skeleton: about, skills, experience, education, projects, contact + footer
- No new codebase pattern learnings — existing patterns from progress.txt covered all needs