- completely redesign hangman game UI with modern styling

- add dark mode support
- implement difficulty settings (easy/medium/hard)
- add local storage for game state persistence
- create modals for win/lose states and settings
- improve hangman canvas drawing with better styling
- add keyboard support for letter input
- implement score tracking and statistics
- add fallback word lists when API fails
- create responsive layout for mobile compatibility

Author: TobiasMue91