[CLAUDE] FE: content polish — typography + PageHeader + Button/Input/Table

Typography base (both apps):
- 14px base, line-height 1.55, letter-spacing -0.003em — Be Vietnam
  Pro render chắc hơn, dấu tiếng Việt rõ hơn
- h1/h2 tracking tighter (-0.018em), h1 weight 700, h2 weight 600
- Tabular numbers trong <table> (tự động align cột số)

PageHeader:
- Title text-[22px] thay vì text-xl — hierarchy mạnh hơn
- Border-bottom + pb-5 thay flat layout — content-area rõ vùng
- Description leading-relaxed + slate-500 — dễ đọc hơn

Button:
- shadow-sm + color-tinted shadow (brand/20, red/20) cho primary/
  danger — có chiều sâu
- active:translate-y-[0.5px] micro-press feedback
- Ring offset 2 (thay 1) + offset-white — focus ring tách rõ

Input/Select/Textarea:
- h-9 thay h-10 — phù hợp dense table layouts
- shadow-[inset_0_1px_0_...] — inset highlight tinh tế
- Focus: border-brand-500 + ring-brand-500/20 — 2 lớp chỉ báo
- Disabled: bg-slate-50 + opacity-70 — rõ disabled state

DataTable:
- rounded-xl + shadow-sm + border-200/80 — card feel nhẹ nhàng hơn
- Header: UPPERCASE text-[11px] tracking-wider — ERP enterprise look
- Row hover: bg-brand-50/40 (thay slate-50) — brand-tinted hover
- Padding tăng từ px-3 py-2 → px-4 py-2.5 — breathing room

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fe-user/src/index.css

@@ -32,12 +32,29 @@ body {
   background-color: #f8fafc;
   color: #0f172a;
   font-family: var(--font-sans);
-  font-feature-settings: "cv11", "ss01", "ss03";
+  font-size: 14px;
+  line-height: 1.55;
+  letter-spacing: -0.003em;
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
   text-rendering: optimizeLegibility;
 }
 
+h1, h2, h3, h4 {
+  letter-spacing: -0.018em;
+  color: #0f172a;
+}
+h1 { font-weight: 700; }
+h2 { font-weight: 600; }
+
+table, .tabular-nums {
+  font-variant-numeric: tabular-nums;
+}
+
+input:focus-visible, textarea:focus-visible, select:focus-visible, button:focus-visible {
+  outline: none;
+}
+
 ::-webkit-scrollbar {
   width: 8px;
   height: 8px;