refactor(shadow): introduce shadow-card utility and extend tailwind-merge

app/(order)/chat/[id]/page.tsx

@@ -62,7 +62,7 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
 
   return (
     <div className="container mx-auto max-w-3xl px-4 py-8 h-[calc(100vh-3.5rem)] flex flex-col">
-      <Card className="flex-1 flex flex-col overflow-hidden hover:shadow-[var(--shadow-card)]">
+      <Card className="flex-1 flex flex-col overflow-hidden hover:shadow-card-hover">
         <div className="border-b px-4 py-3 flex items-center gap-3 bg-muted/30">
           <Link href="/chat" className="text-muted-foreground hover:text-foreground">
             <ArrowLeft className="h-5 w-5" />

app/(order)/chat/page.tsx

@@ -58,7 +58,7 @@ export default function ChatListPage() {
         })}
 
         {sessions.length === 0 && (
-          <Card className="hover:shadow-[var(--shadow-card)]">
+          <Card className="hover:shadow-card-hover">
             <CardContent className="py-8 text-center text-sm text-muted-foreground">
               <MessageSquare className="h-12 w-12 mx-auto mb-2 opacity-50" />
               暂无消息

app/(order)/dispute/[id]/page.tsx

@@ -159,7 +159,7 @@ export default function DisputePage({ params }: { params: Promise<{ id: string }
           返回订单
         </Link>
 
-        <Card className="hover:shadow-[var(--shadow-card)]">
+        <Card className="hover:shadow-card-hover">
           <CardHeader>
             <div className="flex items-center justify-between">
               <CardTitle>争议详情</CardTitle>
@@ -393,7 +393,7 @@ export default function DisputePage({ params }: { params: Promise<{ id: string }
         返回订单
       </Link>
 
-      <Card className="hover:shadow-[var(--shadow-card)]">
+      <Card className="hover:shadow-card-hover">
         <CardHeader>
           <CardTitle className="flex items-center gap-2">
             <AlertTriangle className="h-5 w-5 text-yellow-500" />

app/(order)/orders/page.tsx

@@ -126,14 +126,14 @@ function OrderListContent({
 
         <TabsContent value={tab} className="mt-4 space-y-4">
           {filtered.length === 0 ? (
-            <Card className="hover:shadow-[var(--shadow-card)]">
+            <Card className="hover:shadow-card-hover">
               <CardContent className="py-8 text-center text-sm text-muted-foreground">
                 暂无订单
               </CardContent>
             </Card>
           ) : (
             filtered.map((order) => (
-              <Card key={order.id} className="hover:shadow-[var(--shadow-card)]">
+              <Card key={order.id} className="hover:shadow-card-hover">
                 <CardHeader className="pb-3">
                   <div className="flex items-center justify-between">
                     <CardTitle className="text-base">{order.service.title}</CardTitle>

app/(order)/review/[id]/page.tsx

@@ -86,7 +86,7 @@ export default function ReviewPage({ params }: { params: Promise<{ id: string }>
         返回订单
       </Link>
 
-      <Card className="hover:shadow-[var(--shadow-card)]">
+      <Card className="hover:shadow-card-hover">
         <CardHeader>
           <CardTitle>评价服务</CardTitle>
           <p className="text-sm text-muted-foreground">