:root{--primary:#1d2b7f;--accent:#ff7a00;--ink:#0f172a;--muted:#6b7280;--line:#e5e7eb}
.top-tools{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.lang-switch{display:flex;gap:6px;align-items:center;font-weight:700}
.lang-switch .lang-btn{padding:6px 10px;border-radius:8px;border:1px solid #e5e7eb;background:#fff;cursor:pointer}
.lang-switch .sep{color:#9ca3af}
.coupon-box{display:flex;gap:6px;align-items:center}
.coupon-box input{padding:8px 10px;border:1px solid #d1d5db;border-radius:10px;width:140px}
html.theme-dark{--primary:#9db2ff;--accent:#ff9a3c;--ink:#e5e7eb;--muted:#9ca3af;--line:#232a3b;background:#0b1220}
html.theme-dark body{background:#0b1220;color:var(--ink)}
html.theme-dark header{background:#0b1220;border-bottom-color:#1f2937}
html.theme-dark .card{background:#0f172a;border-color:#334155;box-shadow:none}
html.theme-dark .site-footer{background:#0f172a;color:#cbd5e1}
html.theme-dark .site-footer a{color:#e5e7eb}
html.theme-dark .btn-ghost{background:#111827;border-color:#334155;color:#e5e7eb}
html.theme-dark .coupon-box input{background:#0b1220;color:#e5e7eb;border-color:#334155}
/* Mobile tweaks */
@media (max-width: 640px){
  .brand-slogan{ display:none; }                /* ẩn khẩu hiệu cho gọn */
  .top-tools{ gap:6px; }
  .coupon-box input{ width:110px; }             /* ô mã ngắn lại */
  .lang-switch .lang-btn{ padding:6px 8px; }    /* nút nhỏ hơn chút */
  .btn{ padding:10px 14px; border-radius:10px; }/* dễ bấm */
}