Update color palette and improve UI aesthetics

- Apply new teal-based color palette (#009688, #00796B, #B2DFDB)
- Update secondary color to accent yellow (#FFC107)
- Replace Material-UI loading states with proper animations and skeletons
- Remove ugly gradient background, replace with clean white
- Update all gradients to use new color scheme
- Improve text colors for better readability (#212121, #757575)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/[locale]/page.tsx

@@ -63,7 +63,7 @@ export default function Home() {
       {/* Hero Section */}
       <Box
         sx={{
-          background: 'linear-gradient(135deg, #2C5F6B 0%, #5A8A96 100%)',
+          background: 'linear-gradient(135deg, #009688 0%, #00796B 100%)',
           color: 'white',
           py: 8,
           mb: 6,