Currently, the Pixel Love Letter Generator has a fixed color scheme. It would be great to allow users to choose between different visual themes for the letter and the page. This enhancement will improve the user experience by letting users customize the look and feel according to their preference.

Proposed Enhancement:

Adding a dropdown at the top of the app to select a theme.

Suggested themes:
💗 Romantic (default pixel-pink theme)
📜 Classic (cream & gold tones)
🌙 Night Mode (dark/purple tones)

Theme selection should update the background, letter paper, and text colors dynamically.
Default theme should remain the current romantic style.