/* =====================================================================
   HSK1 3.0 — Premium Dark Theme (app.css)
   Nâng cấp giao diện đồng bộ toàn hệ thống. Nạp SAU <style> nội tuyến
   để ghi đè biến màu + tinh chỉnh linh kiện. Không đổi cấu trúc/logic.
   Nguyên tắc: tương phản đạt chuẩn, chuyển động mượt 150–260ms,
   focus rõ ràng, tôn trọng prefers-reduced-motion, chữ Hán dùng Noto Sans SC.
   ===================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@400;500;600;700;800&family=Baloo+2:wght@600;700;800&family=Noto+Sans+SC:wght@200;300;400;500;700&display=swap');

/* ---------- 1. Bảng màu cao cấp (ghi đè biến gốc) ---------- */
:root{
  --bg:#0a0e1a;
  --card:#12172a;
  --card2:#1a2038;
  --line:#273052;
  --txt:#eaf0ff;
  --muted:#98a4c8;
  --accent:#8b7bfa;      /* violet nhấn phụ (badge) */
  --accent2:#6c8cff;     /* indigo chủ đạo */
  --good:#34d399;        /* emerald */
  --bad:#fb7185;         /* rose */
  --gold:#fbbf24;        /* amber — pinyin & điểm nhấn */
  --pur:#a78bfa;
  --lock:#5b6489;
  --radius:16px;
  --ring:0 0 0 3px rgba(108,140,255,.35);
  --shadow-sm:0 2px 8px rgba(0,0,0,.28);
  --shadow-md:0 10px 26px rgba(0,0,0,.38);
  --shadow-lg:0 18px 46px rgba(0,0,0,.5);
  --ease:cubic-bezier(.4,0,.2,1);
}

/* ---------- 2. Nền & chữ ---------- */
html{scroll-behavior:smooth}
body{
  min-height:100vh;
  background:
    radial-gradient(1200px 720px at 50% -10%, rgba(108,140,255,.18), transparent 60%),
    radial-gradient(820px 560px at 100% -2%, rgba(139,123,250,.16), transparent 55%),
    radial-gradient(720px 560px at 0% 18%, rgba(52,211,153,.07), transparent 55%),
    radial-gradient(1000px 820px at 50% 116%, rgba(108,140,255,.12), transparent 60%),
    linear-gradient(180deg,#080b16 0%,#0a0e1c 45%,#090c18 100%) !important;
  background-attachment:fixed !important;
  color:var(--txt);
  font-family:"Be Vietnam Pro","Segoe UI",system-ui,-apple-system,Roboto,Arial,sans-serif !important;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
/* Lớp kết cấu (dot-grid) mờ để tạo chiều sâu */
body::before{
  content:"";position:fixed;inset:0;z-index:-2;pointer-events:none;
  background-image:radial-gradient(rgba(180,200,255,.05) 1px, transparent 1.4px);
  background-size:24px 24px;
  -webkit-mask-image:radial-gradient(circle at 50% 26%, #000 55%, transparent 100%);
  mask-image:radial-gradient(circle at 50% 26%, #000 55%, transparent 100%);
}
/* Vignette làm tối rìa cho ảnh có chiều sâu */
body::after{
  content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  box-shadow:inset 0 0 260px rgba(0,0,0,.55), inset 0 -120px 200px rgba(4,8,20,.5);
}
::selection{background:rgba(108,140,255,.35);color:#fff}

/* Chữ Hán mượt & rõ nét hơn */
ruby,.han,.h,.cn,.py rt,rt,[lang="zh"],.vtable .h,.w .han,.mcell.han,.fhan,.tzh,.passage,.ans .han,.big-cn,.herocard .big-cn{font-family:"Noto Sans SC","Be Vietnam Pro",system-ui,sans-serif}
/* Chữ Hán MẢNH & thanh thoát (nét nhẹ, đẹp hơn) */
.han,.h,.cn,.vtable .h,.w .han,.mcell.han,.fhan,.tzh,.passage,.ans .han,.qt .han,.big-cn{font-weight:300 !important;letter-spacing:.6px}
/* Tiêu đề dùng font bo tròn thân thiện */
h1,h2,h3,.brand,header.top h1,.bigbtn,.sbtn,.modebtn{font-family:"Baloo 2","Be Vietnam Pro",system-ui,sans-serif !important;letter-spacing:.2px}

/* ---------- 3. Ruby / pinyin ---------- */
ruby rt{
  color:var(--gold);font-weight:500;font-size:.62em;letter-spacing:.3px;
  opacity:.95;line-height:1.1;
}
.py{color:var(--gold)}

/* ---------- 4. Thẻ (card) chung ---------- */
.card,.unit,.prog,.how,.tip,.q,.result,.skbox,.barbox,.vocab,.reveal,.final{
  border-radius:var(--radius);
  border:1px solid var(--line);
  box-shadow:var(--shadow-sm);
}
.card,.unit{
  background:linear-gradient(180deg,rgba(255,255,255,.03),rgba(255,255,255,0)) , var(--card);
  box-shadow:var(--shadow-md);
  transition:border-color .2s var(--ease),box-shadow .25s var(--ease),transform .2s var(--ease);
}
.unit:not(.locked):hover{border-color:rgba(108,140,255,.5);box-shadow:var(--shadow-lg);transform:translateY(-2px)}
.unit.done{border-color:rgba(52,211,153,.5)}

/* ---------- 5. Header trang chủ / badge ---------- */
header.top{
  background:linear-gradient(135deg,#241b4e 0%,#3a2270 45%,#4a2a86 100%) !important;
  border:1px solid rgba(139,123,250,.35) !important;
  box-shadow:0 20px 50px rgba(74,42,134,.4) !important;
  border-radius:22px !important;
}
header.top .cn{background:linear-gradient(90deg,#fff,#d9c8ff);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.badge{
  background:linear-gradient(135deg,var(--accent),var(--accent2)) !important;
  border-radius:999px !important;letter-spacing:.4px;box-shadow:0 4px 12px rgba(108,140,255,.35);
}

/* ---------- 6. Nút bấm ---------- */
.btn,.submit,.act:not(.ghost),.stact a.go,.stact button.go{
  background:linear-gradient(135deg,var(--accent2),#5a78f0) !important;
  color:#fff !important;border:none !important;border-radius:12px !important;
  font-weight:700;cursor:pointer;
  box-shadow:0 6px 16px rgba(108,140,255,.32);
  transition:transform .16s var(--ease),box-shadow .2s var(--ease),filter .2s var(--ease);
}
.btn:hover,.submit:hover,.act:not(.ghost):hover{transform:translateY(-2px);box-shadow:0 10px 24px rgba(108,140,255,.45);filter:brightness(1.06)}
.btn:active,.submit:active,.act:not(.ghost):active{transform:translateY(0)}
.btn.ghost,.act.ghost,.greset{
  background:transparent !important;border:1px solid var(--line) !important;color:var(--txt) !important;
  border-radius:12px !important;cursor:pointer;transition:border-color .2s var(--ease),background .2s var(--ease)}
.btn.ghost:hover,.act.ghost:hover,.greset:hover{border-color:var(--accent2) !important;background:rgba(108,140,255,.08) !important}

/* Nút loa/audio */
.audio,.vplay{
  cursor:pointer;border-radius:10px !important;
  transition:transform .15s var(--ease),background .2s var(--ease),border-color .2s var(--ease)}
.audio:hover,.vplay:hover{transform:scale(1.06)}

/* ---------- 7. Đáp án trắc nghiệm (opt) ---------- */
.opt{
  border-radius:12px !important;border:1px solid var(--line) !important;cursor:pointer;
  transition:border-color .18s var(--ease),background .18s var(--ease),transform .12s var(--ease);
}
.opt:hover{border-color:var(--accent2) !important;background:rgba(108,140,255,.08) !important;transform:translateX(2px)}
.opt.correct{background:rgba(52,211,153,.18) !important;border-color:var(--good) !important}
.opt.wrong{background:rgba(251,113,133,.16) !important;border-color:var(--bad) !important}

/* ---------- 8. Icon ô vuông (uico) & số thứ tự ---------- */
.uico{
  background:linear-gradient(135deg,rgba(108,140,255,.18),rgba(139,123,250,.14)) !important;
  border:1px solid rgba(108,140,255,.32) !important;border-radius:14px !important}
.stnum,.qnum,.n,.sk{border-radius:12px}
.step.active .stnum{background:var(--accent2);border-color:var(--accent2);box-shadow:0 4px 12px rgba(108,140,255,.4)}

/* ---------- 9. Thanh tiến trình ---------- */
.pbar,.progress,.scorebar,.barbox .bar{border-radius:999px !important;overflow:hidden}
.pbar>i,.progress>i{background:linear-gradient(90deg,var(--accent2),var(--good)) !important}

/* ---------- 10. Bảng từ vựng ---------- */
.vtable{border-collapse:separate;border-spacing:0;overflow:hidden;border-radius:14px}
.vtable td{border-color:var(--line) !important}
.vtable .h{font-family:"Noto Sans SC",sans-serif;font-weight:700}
.vtable tr{transition:background .15s var(--ease)}
.vtable tr:hover td{background:rgba(108,140,255,.06)}

/* ---------- 11. Ô nhập liệu (gõ pinyin) ---------- */
input[type="text"],input:not([type]){
  border-radius:10px !important;border:1px solid var(--line) !important;
  background:var(--card2) !important;color:var(--txt) !important;
  transition:border-color .18s var(--ease),box-shadow .18s var(--ease)}
input[type="text"]:focus,input:not([type]):focus{outline:none;border-color:var(--accent2) !important;box-shadow:var(--ring)}

/* ---------- 12. Liên kết Trang chủ ---------- */
a.home{color:var(--accent2);font-weight:600;transition:opacity .2s var(--ease)}
a.home:hover{opacity:.75}

/* ---------- 13. Focus rõ ràng cho bàn phím ---------- */
a:focus-visible,button:focus-visible,.opt:focus-visible,input:focus-visible{outline:none;box-shadow:var(--ring);border-radius:10px}

/* ---------- 14. Tôn trọng người dùng tắt hiệu ứng ---------- */
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms !important;transition-duration:.001ms !important;scroll-behavior:auto !important}
}