Refactor forms and uploader components UI with Card layout

Updated color, font, and asset forms to use Card and CardContent for improved structure and consistency. Enhanced input styles and hover effects for better user experience. Adjusted the image uploader background for a more cohesive design.

frontend/src/components/ui/image-uploader.tsx

@@ -123,7 +123,8 @@ export function ImageUploader({
       )}
 
       <div
-        className={`relative border-2 border-dashed border-gray-300 rounded-md ${getAspectRatioClass()} overflow-hidden bg-gray-50 hover:bg-gray-100 transition-colors`}
+        className={`relative border-2 border-dashed border-border rounded-md ${getAspectRatioClass()} 
+                    overflow-hidden bg-muted/30 hover:bg-muted/50 transition-colors`}
       >
         {/* Hidden file input */}
         <input