- refactor alphabet game UI with responsive design and modern styling

- implement detailed letter-by-letter performance tracking and statistics
- add visual performance charts for historical attempts
- integrate persistent storage for user progress and high scores
- introduce game states (ready, playing, completed, error) for better UX
- add visual feedback with animations for typing events
- implement tabbed interface for statistics, history, and letter timing data
- add SEO metadata and Schema.org markup

Author: TobiasMue91