feat: 统一页面布局与字体样式

frontend/src/pages/Dashboard.tsx

@@ -158,8 +158,11 @@ export default function Dashboard() {
     <div className="space-y-3">
       <div className="flex items-center justify-between">
         <div>
-          <h1 className="text-xs font-medium">{data.greeting}</h1>
-          <p className="text-xs text-gray-500 mt-0.5">{payroll?.month} 月度总览</p>
+          <div className="flex items-center gap-2">
+            <LayoutDashboard className="h-5 w-5 text-primary" />
+            <h1 className="text-base font-semibold">工作台</h1>
+          </div>
+          <p className="mt-1 text-sm text-gray-500">{data.greeting} · {payroll?.month} 月度总览</p>
         </div>
         <Button variant="secondary" size="sm" onClick={() => refetch()} disabled={isFetching} className={activeTab === 'risk' || activeTab === 'task' ? 'opacity-50 pointer-events-none' : ''}>
           <RefreshCw className={`w-4 h-4 mr-1 ${isFetching ? 'animate-spin' : ''}`} />
@@ -175,7 +178,7 @@ export default function Dashboard() {
             <button
               key={tab.key}
               onClick={() => setActiveTab(tab.key)}
-              className={`flex items-center gap-1.5 px-3 py-1.5 text-xs font-medium border-b-2 transition-colors ${
+              className={`flex items-center gap-1.5 px-4 py-2 text-sm font-medium border-b-2 transition-colors ${
                 activeTab === tab.key ? 'border-primary text-primary' : 'border-transparent text-gray-500 hover:text-gray-700'
               }`}
             >