refactor: update global styles and remove unused color definitions

- Added a configuration reference to Tailwind in globals.css.
- Removed the colors.css file and the previous globals.css file to clean up unused styles.

src/app/globals.css

@@ -1,3 +1,4 @@
+@config "../../tailwind.config.ts";
 @tailwind base;
 @tailwind components;
 @tailwind utilities;