Increase border radius for modern rounded inputs and buttons

Makes form controls more rounded and polished instead of rectangular:

Form control updates:
- Increase border-radius from 0.5rem to 0.75rem for softer curves
- Increase border from 1px to 2px for better definition
- Adjust padding to 0.75rem 1rem for comfortable spacing
- Set font-size to 1rem for better readability

Button updates:
- Match border-radius at 0.75rem for consistency
- Increase font-weight to 600 for emphasis
- Add explicit padding (0.75rem 1.5rem)
- Stronger hover lift effect (translateY -2px)
- Enhanced shadow on hover (0 4px 12px)

Inputs and buttons now have modern, rounded appearance matching
the design system used throughout the application.

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

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

app/views/pay/index.html.erb

@@ -412,10 +412,10 @@ $(document).on('turbolinks:load', function() {
 
   /* Clean, minimal form controls */
   .form-control {
-    border-radius: 0.5rem;
-    border: 1px solid #dee2e6;
-    padding: 0.625rem 0.875rem;
-    font-size: 0.95rem;
+    border-radius: 0.75rem;
+    border: 2px solid #e9ecef;
+    padding: 0.75rem 1rem;
+    font-size: 1rem;
     transition: all 0.2s ease;
   }
 
@@ -444,13 +444,14 @@ $(document).on('turbolinks:load', function() {
 
   /* Button styling */
   .btn {
-    border-radius: 0.5rem;
-    font-weight: 500;
+    border-radius: 0.75rem;
+    font-weight: 600;
     transition: all 0.2s ease;
+    padding: 0.75rem 1.5rem;
   }
 
   .btn:hover {
-    transform: translateY(-1px);
-    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
+    transform: translateY(-2px);
+    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
   }
 </style>