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/globals.css

@@ -18,12 +18,7 @@
 
 body {
   color: rgb(var(--foreground-rgb));
-  background: linear-gradient(
-      to bottom,
-      transparent,
-      rgb(var(--background-end-rgb))
-    )
-    rgb(var(--background-start-rgb));
+  background: white;
 }
 
 .verse {