refactor: standardize background color to #121212

- Replaced inconsistent gray-900 and #171717 background colors with unified #121212 across all pages
- Removed unused imports from multiple component files
- Cleaned up trailing spaces in className attributes

src/main.tsx

@@ -1,7 +1,7 @@
 import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
 import './styles/tailwind.css'
-import App from './App.tsx'
+import App from './App'
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>