remove explicit coloring from shadcn summary card

src/app/page.tsx

@@ -251,8 +251,8 @@ export default function HomePage() {
       {/* Summary Panel */}
       {
         summary && (
-          <Card className="p-4 mb-4 bg-gray-50 border border-gray-200">
-            <div className="text-sm text-gray-500 mb-1">
+          <Card className="p-4 mb-4">
+            <div className="text-sm mb-1">
               Summary updated {summaryUpdated}
             </div>
             <div>{summary}</div>