feat: Sprint 1 — 设计Token系统 + 新导航5分组 + AppShell/PageHeader/FilterBar/DataTable组件 + 花名册导出扩充19字段 + 社保/公积金不缴纳选项 + 个税申报表导出 + 入离职/绩效统计看板

frontend/src/index.css

@@ -4,9 +4,10 @@
 
 @layer base {
   body {
-    @apply bg-surface text-gray-900 antialiased;
-    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
-    font-size: 16px;
+    @apply bg-surface-page text-ink-900 antialiased;
+    font-family: Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
+    font-variant-numeric: tabular-nums;
+    font-size: 14px;
     line-height: 1.5;
     -webkit-tap-highlight-color: transparent;
     -webkit-touch-callout: none;
@@ -29,22 +30,22 @@
     @apply inline-flex items-center justify-center px-3 py-1.5 rounded font-medium text-sm transition-colors disabled:opacity-50 disabled:cursor-not-allowed;
   }
   .btn-primary {
-    @apply btn bg-primary text-white hover:bg-primary-dark;
+    @apply btn bg-brand-600 text-white hover:bg-brand-700;
   }
   .btn-secondary {
-    @apply btn bg-gray-100 text-gray-700 hover:bg-gray-200;
+    @apply btn bg-surface-muted text-ink-700 hover:bg-border-subtle;
   }
   .btn-danger {
-    @apply btn bg-danger text-white hover:bg-red-700;
+    @apply btn bg-danger text-white hover:bg-danger-light;
   }
   .card {
-    @apply bg-white rounded-lg shadow-sm border border-gray-200 p-4;
+    @apply bg-surface-card rounded-card border border-border-default;
   }
   .input {
-    @apply w-full px-2.5 py-1.5 rounded-md border border-gray-300 focus:outline-none focus:ring-2 focus:ring-primary focus:border-transparent text-sm;
+    @apply w-full px-2.5 py-2 rounded-md border border-border-default bg-surface-card text-sm text-ink-900 focus:outline-none focus:ring-2 focus:ring-brand-600/30 focus:border-brand-600 transition-colors;
   }
   .label {
-    @apply block text-sm font-medium text-gray-700 mb-1;
+    @apply block text-sm font-medium text-ink-700 mb-1;
   }
 }