- Add comprehensive design tokens (spacing, colors, typography, sizing)
- Introduce CSS layers (base, components, utilities) for better organization
- Replace inline utility classes with semantic component classes (.card, .btn, .form-*)
- Update Avatar to use new .avatar classes instead of inline styles
- Update QuestionCard to use .question-card component classes
- Refactor all routes to use new design system and layout classes
- Add new components: .header, .container, .stack, .feed, .status-badge
- Establish consistent spacing using Fibonacci sequence
- Improve visual hierarchy with semantic typography classes