feat: Implement consistent section card styling across contest view (#167)

feat: Implement consistent section card styling across contest view

- Unified all sections (Contest Details, Scoring System, Rules, etc.)
with .section-card class
- Added full-width blue headers for all content sections
- Fixed organizer and jury member chip text color to white
- Improved visual consistency and user experience
- Enhanced dark mode support for all sections
- Maintained all existing functionality and information display

Author: GauriGupta21