refactor: update content card and list layout for better responsiveness

- Removed unused aspect-video class from content card layout.
- Improved content list layout by switching to a responsive grid system.

frontend/src/components/content-card.tsx

@@ -158,7 +158,7 @@ export function ContentCard({ content, onUpdate }: ContentCardProps) {
 						</DropdownMenu>
 					</div>
 				</CardHeader>
-				<CardContent className="p-0 relative bg-zinc-200 dark:bg-zinc-900 aspect-square sm:aspect-video md:aspect-square flex items-center justify-center">
+				<CardContent className="p-0 relative bg-zinc-200 dark:bg-zinc-900 aspect-square flex items-center justify-center">
 					<Link href={`/meme/${content.slug}`} className="w-full h-full relative">
 						{content.mimeType.startsWith("image/") ? (
 							<Image