Frontend cleanup

[bbbreaddd]

Mostly just cleaning up the Frontend, some refactoring, and polishing. Hopefully to make it more maintainable and less fragile.
Preview: https://d01bc7ae.edit-b69.pages.dev/
Improvements:

• Improved navbar padding (768px–959px) to prevent buttons being cropped out
• Unified themes and colors instead of it being different systems and conflicting with each other.
• Removed unused theme rules and simplified themes
• Added active theme indicator since it seemed to either be broken or unfinished.
• Cleaner June theme logic
• Fixed UnoCSS breaking VitePress' sub-nav bar
• Removed unused dependencies and replaced some with already native logic or existing dependencies so we don't need as many dependencies
  The rest of the changes are mostly just removing really old code that was added a long time ago, but has since been disabled or unused. Behavior is pretty much the same other than the small fixes shown in the pictures.

Active theme indicator

Button being covered at a certain view

On this page button not spanning the full width of the screen

On this page button aligning to the left rather than the right in a certain view