update:css样式拆分

frontend/app/routes/platform.tsx

@@ -18,8 +18,6 @@ import { useUiStore } from "../features/platform/state/uiStore";
 import { bindAdminApi } from "../features/admin/state/adminStore";
 import { bindSchedulesApi } from "../features/schedules/state/useSchedulesStore";
 
-import "../styles/platform.css";
-
 type ActivePage = "home" | "scripts" | "schedules" | "system";
 
 function pageFromPath(pathname: string): ActivePage {
@@ -45,12 +43,9 @@ export default function PlatformLayout() {
   const { currentWorkspace } = useAuth();
   if (!currentWorkspace) {
     return (
-      <div
-        className="app-shell"
-        style={{ display: "flex", alignItems: "center", justifyContent: "center" }}
-      >
-        <div style={{ textAlign: "center" }}>
-          <span style={{ fontSize: 18 }}>加载中…</span>
+      <div className="flex min-h-screen items-center justify-center bg-[#eef2f6]">
+        <div className="text-center">
+          <span className="text-lg">加载中…</span>
         </div>
       </div>
     );
@@ -116,7 +111,7 @@ function AuthenticatedLayout() {
   }, [toast, dismissToast]);
 
   return (
-    <div className="app-shell">
+    <div className="flex min-h-screen bg-[#eef2f6]">
       <Sidebar
         activePage={activePage}
         collapsed={sidebarCollapsed}
@@ -128,7 +123,7 @@ function AuthenticatedLayout() {
         isSystemAdmin={user?.is_system_admin ?? false}
       />
 
-      <main className="main-area">
+      <main className="flex h-screen min-w-0 flex-1 flex-col">
         <Topbar
           activePage={activePage}
           apiOnline={apiOnline}