- Create kpi_card() component with icon, value, label, and highlight option
- Create kpi_row() with 4 KPI cards: Unique Patients, Drug Types, Total Cost, Indication Match
- Add computed vars for formatted KPI display values
- Add placeholder KPI state variables (unique_patients, total_drugs, total_cost, indication_match_rate)
- Use design system tokens for styling with hover effects
- Responsive flex-wrap layout for smaller screens
- Add date_range_picker() component with enable/disable checkbox
- Add searchable_dropdown() component with search, select all, clear
- Implement filter_section() with layout for dates and multi-selects
- Add comprehensive state management in AppState:
- Filter toggle states (initiated_filter_enabled, last_seen_filter_enabled)
- Date values for both ranges
- Dropdown visibility state
- Selection state for drugs, indications, directorates
- Search text state for filtering options
- Event handlers for all filter interactions
- Computed vars for filtered options and selection counts
- Style components using design tokens from styles.py
- Debounced handlers deferred to Phase 3.3 (Filter Logic)
- Add chart_tab() component for chart type pills
- Implement full top_bar() with logo, title, chart tabs, data freshness
- Heritage Blue background with white text, 64px fixed height
- Reactive data freshness indicator using rx.cond for loading states
- Added Transitions import to styles
- Add app_v2.py with basic Reflex app structure
- AppState class with placeholder state variables
- Layout components: top_bar, filter_section, kpi_row, chart_section
- Page layout matching DESIGN_SYSTEM.md structure
- Theme configured with design system colors
- Google Fonts for Inter and JetBrains Mono
- Add Colors class with NHS-inspired blue palette and neutrals
- Add Typography class with font family, sizes, weights
- Add Spacing, Radii, Shadows, Transitions classes
- Add helper functions: card_style(), button_*_style(), input_style()
- Add KPI card and text style helpers
- Add layout constants (TOP_BAR_HEIGHT, PAGE_MAX_WIDTH)
All tokens match DESIGN_SYSTEM.md specifications.