- complete redesign of website UI/UX with modern, responsive layout

- implement data-driven approach with new `games.json` and `tools.json` files
- add dynamic content loading with animation effects
- add mobile-friendly navigation with hamburger menu
- implement CSS variables for consistent theming
- move chat toggle button to left side of screen
- add back-to-top button and section navigation
- implement loading states for content areas

Author: TobiasMue91