完整性更新

现在已经实现了大部分基础功能

src/app/(dashboard)/student/learning/courses/loading.tsx

@@ -0,0 +1,29 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="flex h-full flex-col space-y-8 p-8">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-40" />
+        <Skeleton className="h-4 w-52" />
+      </div>
+
+      <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-3">
+        {Array.from({ length: 6 }).map((_, i) => (
+          <Card key={i}>
+            <CardHeader className="pb-2">
+              <Skeleton className="h-5 w-44" />
+              <Skeleton className="mt-2 h-4 w-56" />
+            </CardHeader>
+            <CardContent className="pt-2 flex items-center justify-between">
+              <Skeleton className="h-4 w-40" />
+              <Skeleton className="h-9 w-24" />
+            </CardContent>
+          </Card>
+        ))}
+      </div>
+    </div>
+  )
+}
+