refactor(ui): reduce IconButton size by 25%

- Change default size from 44px to 33px (25% reduction)
- Update min-width and min-height in CSS to match
- Apply size reduction to toggle-sidebar-btn as well for consistency

src/components/IconButton.tsx

@@ -17,7 +17,7 @@ const IconButton: React.FC<IconButtonProps> = ({
   title,
   ariaLabel,
   variant = 'ghost',
-  size = 44
+  size = 33
 }) => {
   return (
     <button

src/index.css

@@ -130,8 +130,8 @@ body {
   display: flex;
   align-items: center;
   justify-content: center;
-  min-width: 44px;
-  min-height: 44px;
+  min-width: 33px;
+  min-height: 33px;
 }
 
 .toggle-sidebar-btn:hover {
@@ -224,8 +224,8 @@ body {
   background: #2a2a2a;
   color: #ddd;
   cursor: pointer;
-  min-width: 44px; /* mobile tap target */
-  min-height: 44px; /* mobile tap target */
+  min-width: 33px;
+  min-height: 33px;
 }
 
 .icon-button:hover { background: #333; }