The duplicate functions at lines 455-486 were redefining cacheElements and
bindEvents with wrong element IDs (kebab-case vs camelCase in HTML).
This caused 'Cannot read properties of null' error on slides app init.
- Remove intermediate variable aliases in :root (they don't cascade)
- Replace --sheet-* and --slides-* with direct --sentient-* references
- Headers, borders, and cells now properly follow theme colors
- Dark themes will now paint dark backgrounds correctly
- Clean editor experience without document list sidebars
- Theme-aware using --sentient-* CSS variables
- Modern toolbar design like Microsoft 365
- Sheet: Formula bar, spreadsheet grid, sheet tabs, zoom controls
- Docs: A4 page centered with shadow, formatting toolbar
- Slides: Thumbnails on left, canvas in center, properties panel
- AI chat panel (collapsible) for all editors
- Responsive design with mobile support
- Print styles for all editors
- Dark/light mode support via theme system
- Add JavaScript to load user profile from /api/auth/me endpoint
- Save access_token to localStorage/sessionStorage on login
- Update user menu to show actual user name and email
- Toggle Sign in/Sign out based on authentication state
- Add IDs to user menu elements for dynamic updates
