5.3 글로벌 로딩/스켈레톤/에러 경계 패턴 정립 o

src/app/loading.tsx

@@ -0,0 +1,18 @@
+export default function Loading() {
+  return (
+    <div style={{ padding: 24 }}>
+      <div style={{
+        width: 48,
+        height: 48,
+        borderRadius: "50%",
+        border: "4px solid #eee",
+        borderTopColor: "#111",
+        animation: "spin 1s linear infinite",
+        margin: "24px auto",
+      }} />
+      <style>{`@keyframes spin{to{transform:rotate(360deg)}}`}</style>
+    </div>
+  );
+}
+
+