# Mobile Implementation Summary

## Overview
Boris is now mobile-friendly! The app now works seamlessly on mobile devices with a responsive design that includes:
- Auto-collapsing sidebar that opens as an overlay drawer on small screens
- Touch-optimized UI with proper touch target sizes (44x44px minimum)
- Safe area insets for notched devices (iPhone X+, etc.)
- Focus trap and keyboard navigation in the mobile sidebar
- Mobile-optimized modals, toasts, and other UI elements

## Changes Made

### 1. Viewport & Base Setup
**File: `index.html`**
- Updated viewport meta tag to include `viewport-fit=cover` for proper safe area handling

### 2. Media Query Hooks
**File: `src/hooks/useMediaQuery.ts` (NEW)**
- `useMediaQuery(query)` - Generic hook for any media query
- `useIsMobile()` - Detects mobile viewport (≤768px)
- `useIsTablet()` - Detects tablet viewport (≤1024px)
- `useIsCoarsePointer()` - Detects touch devices

### 3. Mobile CSS Styles
**File: `src/index.css`**
- Added CSS custom properties for mobile breakpoints and safe areas
- Mobile-specific three-pane layout that stacks into single column
- Overlay sidebar with backdrop and transitions
- Touch target improvements (44x44px minimum)
- Disabled hover effects on touch devices
- Mobile-optimized modals (full-screen sheet style)
- Mobile-optimized toasts (bottom position with safe area)
- Dynamic viewport height support (`100dvh`)
- Overscroll behavior and body scroll locking

### 4. Sidebar State Management
**File: `src/hooks/useBookmarksUI.ts`**
- Added `isMobile` state from media query
- Added `isSidebarOpen` state for mobile overlay
- Added `toggleSidebar()` function
- Auto-collapse logic based on `autoCollapseSidebarOnMobile` setting
- Mobile sidebar defaults to closed, desktop defaults to open

### 5. Three-Pane Layout Mobile Support
**File: `src/components/ThreePaneLayout.tsx`**
- Mobile hamburger button (visible only on mobile)
- Mobile backdrop for closing sidebar
- Body scroll locking when sidebar is open
- ESC key handler to close sidebar
- Focus trap in sidebar (Tab navigation stays within sidebar)
- Focus restoration when closing sidebar
- Accessibility attributes (`aria-hidden`, `aria-expanded`, etc.)

### 6. Sidebar Header Mobile Controls
**File: `src/components/SidebarHeader.tsx`**
- Close button (X) visible on mobile instead of collapse chevron
- Hamburger button hidden in header (shown in layout instead)

### 7. Bookmark List Mobile Props
**File: `src/components/BookmarkList.tsx`**
- Added `isMobile` prop support
- Passes mobile state to SidebarHeader

### 8. Main Bookmarks Component
**File: `src/components/Bookmarks.tsx`**
- Uses mobile state from `useBookmarksUI`
- Auto-closes sidebar when selecting bookmark on mobile
- Closes sidebar when opening settings on mobile
- Proper desktop/mobile toggle behavior

### 9. Icon Button Enhancement
**File: `src/components/IconButton.tsx`**
- Added optional `className` prop for additional styling

### 10. Mobile Settings
**File: `src/services/settingsService.ts`**
- Added `autoCollapseSidebarOnMobile?: boolean` setting (default: true)

**File: `src/components/Settings/StartupPreferencesSettings.tsx`**
- Added UI toggle for "Auto-collapse sidebar on small screens"

## Accessibility Features
- Focus trap in mobile sidebar (Tab key navigation stays within drawer)
- ESC key closes mobile sidebar
- Backdrop click closes mobile sidebar
- Proper ARIA attributes (`aria-hidden`, `aria-expanded`, `aria-controls`)
- Touch target minimum size enforcement (44x44px)
- Focus restoration when closing sidebar

## Mobile Behaviors
1. **Sidebar**: Slides in from left as overlay drawer with backdrop
2. **Hamburger Menu**: Fixed position top-left when sidebar closed
3. **Selecting Content**: Auto-closes sidebar on mobile
4. **Opening Settings**: Auto-closes sidebar on mobile
5. **Highlights Panel**: Hidden on mobile (content takes full width)
6. **Modals**: Full-screen sheet style from bottom
7. **Toasts**: Bottom position with safe area padding

## Responsive Breakpoints
- **Mobile**: ≤768px (sidebar overlay, single column)
- **Tablet**: ≤1024px (defined but not actively used yet)
- **Desktop**: >768px (three-pane layout as before)

## Browser Support
- Modern browsers with CSS Grid support
- iOS Safari (including safe area insets)
- Chrome for Android
- Firefox Mobile
- Safari on iPadOS

## Safe Area Support
The app respects device safe areas (notches, home indicators) through CSS environment variables:
- `env(safe-area-inset-top)`
- `env(safe-area-inset-bottom)`
- `env(safe-area-inset-left)`
- `env(safe-area-inset-right)`

## Future Enhancements
Potential improvements for future iterations:
- Swipe gesture to open/close sidebar
- Pull-to-refresh on mobile
- Bottom sheet for highlights panel on mobile
- Optimized font sizes for mobile reading
- Mobile-specific view mode (perhaps auto-switch to compact on mobile)
- Haptic feedback on interactions (iOS/Android)
- Share sheet integration
- Install prompt for PWA

## Testing Checklist
- [x] Sidebar opens/closes on mobile
- [x] Hamburger button visible on mobile
- [x] Backdrop closes sidebar
- [x] ESC key closes sidebar
- [x] Focus trap works in sidebar
- [x] Selecting bookmark closes sidebar
- [x] No horizontal scroll
- [x] Touch targets ≥ 44px
- [x] Modals are full-screen on mobile
- [x] Toasts appear at bottom with safe area
- [x] Build completes without errors
- [ ] Test on actual iOS device (iPhone)
- [ ] Test on actual Android device
- [ ] Test with keyboard navigation
- [ ] Test with screen reader
- [ ] Test landscape orientation
- [ ] Test on various screen sizes (320px, 375px, 414px, 768px)

## Commit History
1. `feat: update viewport meta for mobile support`
2. `feat: add media query hooks for responsive design`
3. `feat: add mobile sidebar state management to useBookmarksUI`
4. `feat: add mobile-responsive CSS with breakpoints and safe areas`
5. `feat: implement mobile overlay sidebar with focus trap and ESC handling`
6. `feat: add mobile auto-collapse setting`
7. `fix: resolve TypeScript errors for mobile implementation`