refactor(admin): 替换硬编码 gray/white 为设计 token(login + layout)

- login/page.tsx、admin-layout.tsx 全部 Tailwind gray-* / bg-white / bg-black/50 映射至语义 token
- 深色面板(bg-gray-900/800 激活态、头像、登录按钮)映射 bg-dark-bg / bg-dark-bg-secondary,保持两模式深色
- 深色面板上的文字用 text-dark-text-primary(固定亮色),规避 text-white 在暗黑模式反色为暗的陷阱
- 遮罩 bg-black/50 → bg-overlay/50(独立 token,不随反色)
- 验证: type-check 0 / lint 0 / 产物 CSS 已含全部映射类

src/components/admin/admin-layout.tsx

@@ -139,28 +139,28 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
   };
 
   return (
-    <div className="min-h-screen bg-gray-50">
+    <div className="min-h-screen bg-bg-secondary">
       {/* Mobile overlay */}
       {sidebarOpen && (
         <div
-          className="fixed inset-0 bg-black/50 z-40 lg:hidden"
+          className="fixed inset-0 bg-overlay/50 z-40 lg:hidden"
           onClick={() => setSidebarOpen(false)}
         />
       )}
 
       {/* Sidebar */}
       <aside
-        className={`fixed top-0 left-0 z-50 h-full w-64 bg-white border-r border-gray-200 transform transition-transform duration-200 ease-in-out lg:translate-x-0 ${
+        className={`fixed top-0 left-0 z-50 h-full w-64 bg-bg-primary border-r border-border-primary transform transition-transform duration-200 ease-in-out lg:translate-x-0 ${
           sidebarOpen ? 'translate-x-0' : '-translate-x-full'
         }`}
       >
-        <div className="flex items-center justify-between h-16 px-4 border-b border-gray-200">
+        <div className="flex items-center justify-between h-16 px-4 border-b border-border-primary">
           <Link href="/admin" className="flex items-center gap-2">
-            <span className="text-lg font-bold text-gray-900">Novalon CMS</span>
+            <span className="text-lg font-bold text-text-primary">Novalon CMS</span>
           </Link>
           <button
             onClick={() => setSidebarOpen(false)}
-            className="lg:hidden p-1 rounded hover:bg-gray-100"
+            className="lg:hidden p-1 rounded hover:bg-bg-hover"
           >
             <X className="w-5 h-5" />
           </button>
@@ -172,8 +172,8 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
             href="/admin"
             className={`flex items-center gap-3 px-3 py-2.5 rounded-lg text-sm font-medium transition-colors ${
               pathname === '/admin'
-                ? 'bg-gray-900 text-white'
-                : 'text-gray-600 hover:bg-gray-100'
+                ? 'bg-dark-bg text-dark-text-primary'
+                : 'text-text-tertiary hover:bg-bg-hover'
             }`}
           >
             <LayoutDashboard className="w-4 h-4" />
@@ -189,8 +189,8 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
                 onClick={() => toggleMenu(group.label)}
                 className={`flex items-center justify-between w-full px-3 py-2.5 rounded-lg text-sm font-medium transition-colors ${
                   hasActiveChild
-                    ? 'bg-gray-100 text-gray-900'
-                    : 'text-gray-600 hover:bg-gray-100'
+                    ? 'bg-bg-hover text-text-primary'
+                    : 'text-text-tertiary hover:bg-bg-hover'
                 }`}
               >
                 <span className="flex items-center gap-3">
@@ -212,8 +212,8 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
                       href={item.href}
                       className={`flex items-center gap-3 px-3 py-2 rounded-lg text-sm transition-colors ${
                         isActive(item.href)
-                          ? 'bg-gray-900 text-white'
-                          : 'text-gray-500 hover:bg-gray-100'
+                          ? 'bg-dark-bg text-dark-text-primary'
+                          : 'text-text-muted hover:bg-bg-hover'
                       }`}
                     >
                       <item.icon className="w-3.5 h-3.5" />
@@ -228,20 +228,20 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
         </nav>
 
         {/* User info */}
-        <div className="border-t border-gray-200 p-3">
+        <div className="border-t border-border-primary p-3">
           <div className="flex items-center gap-3 px-3 py-2">
-            <div className="w-8 h-8 rounded-full bg-gray-900 text-white flex items-center justify-center text-sm font-medium">
+            <div className="w-8 h-8 rounded-full bg-dark-bg text-dark-text-primary flex items-center justify-center text-sm font-medium">
               {user?.nickname?.charAt(0) || 'A'}
             </div>
             <div className="flex-1 min-w-0">
-              <p className="text-sm font-medium text-gray-900 truncate">
+              <p className="text-sm font-medium text-text-primary truncate">
                 {user?.nickname || user?.username}
               </p>
-              <p className="text-xs text-gray-500">{user?.role === 'admin' ? '管理员' : '编辑'}</p>
+              <p className="text-xs text-text-muted">{user?.role === 'admin' ? '管理员' : '编辑'}</p>
             </div>
             <button
               onClick={handleLogout}
-              className="p-1.5 rounded hover:bg-gray-100 text-gray-400 hover:text-red-500 transition-colors"
+              className="p-1.5 rounded hover:bg-bg-hover text-text-muted hover:text-red-500 transition-colors"
               title="退出登录"
             >
               <LogOut className="w-4 h-4" />
@@ -253,10 +253,10 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
       {/* Main content */}
       <div className="lg:pl-64">
         {/* Top bar */}
-        <header className="sticky top-0 z-30 h-16 bg-white border-b border-gray-200 flex items-center justify-between px-4 lg:px-6">
+        <header className="sticky top-0 z-30 h-16 bg-bg-primary border-b border-border-primary flex items-center justify-between px-4 lg:px-6">
           <button
             onClick={() => setSidebarOpen(true)}
-            className="lg:hidden p-2 rounded hover:bg-gray-100"
+            className="lg:hidden p-2 rounded hover:bg-bg-hover"
           >
             <Menu className="w-5 h-5" />
           </button>
@@ -267,7 +267,7 @@ export function AdminLayout({ children }: { children: React.ReactNode }) {
             <Link
               href="/"
               target="_blank"
-              className="text-sm text-gray-500 hover:text-gray-700 transition-colors"
+              className="text-sm text-text-muted hover:text-text-secondary transition-colors"
             >
               查看网站
             </Link>