fix: unify FeedPreviewCard layout and styling

- Removed border and background classes for a cleaner look.
- Adjusted padding and icon size for improved visual consistency.

Signed-off-by: Innei <tukon479@gmail.com>

apps/desktop/layer/renderer/src/components/ui/hover-preview/FeedPreviewCard.tsx

@@ -43,7 +43,7 @@ export const FeedPreviewCard: React.FC<FeedPreviewCardProps> = ({
         >
           {/* Header */}
           <a
-            className="border-b border-border bg-fill-tertiary p-4"
+            className="p-4"
             href={feed.url ?? "#"}
             onClick={(e) => {
               e.preventDefault()
@@ -52,8 +52,8 @@ export const FeedPreviewCard: React.FC<FeedPreviewCardProps> = ({
             target="_blank"
             rel="noopener noreferrer"
           >
-            <div className="flex items-start gap-3">
-              <FeedIcon target={feed} size={40} className="shrink-0" />
+            <div className="flex items-start gap-3 pl-4">
+              <FeedIcon target={feed} size={32} className="shrink-0" />
               <div className="min-w-0 flex-1">
                 <div className="flex items-center gap-2">
                   <h3 className="line-clamp-1 text-sm font-semibold text-text">{feed.title}</h3>