/* ============================================================
   手指鼓 Finger Drum — official site
   Dark + amber instrument-brand language (matches app handoff)
   ============================================================ */
:root{
  --bg:#0c0d0f;
  --stage:#070708;
  --panel:#15171b;
  --panel-2:#1c2025;
  --panel-3:#23272d;
  --line:#2a2f36;
  --line-soft:#1f2329;
  --text:#edeff2;
  --dim:#9aa0a9;
  --dim-2:#646a73;
  --amber:#f4a52b;
  --amber-2:#ffc266;
  --amber-soft:rgba(244,165,43,.13);
  --amber-line:rgba(244,165,43,.42);
  --rec:#ef5340;
  --maxw:1180px;
  --r:18px;
  --ease:cubic-bezier(.32,.72,0,1);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--stage);
  color:var(--text);
  font-family:"Plus Jakarta Sans",system-ui,sans-serif;
  -webkit-font-smoothing:antialiased;
  line-height:1.6;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;cursor:pointer;border:none;background:none}
img{max-width:100%;display:block}

/* bilingual: html[data-lang] gates which language nodes show */
html[data-lang="zh"] [lang="en"]{display:none !important}
html[data-lang="en"] [lang="zh"]{display:none !important}

/* ---------- layout helpers ---------- */
.wrap{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 28px}
.eyebrow{font-size:13px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--amber)}
section{position:relative}

/* ---------- pad-grid logo mark ---------- */
.mark{width:30px;height:30px;border-radius:8px;overflow:hidden;flex:0 0 auto;
  background:linear-gradient(160deg,#22262b,#0f1113);position:relative;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.05)}
.mark .pg{position:absolute;inset:5px;display:grid;grid-template-columns:1fr 1fr;grid-template-rows:1fr 1fr;gap:2.5px}
.mark .p{border-radius:2.5px;background:linear-gradient(170deg,#31363d,#262a30)}
.mark .p.lit{background:linear-gradient(165deg,var(--amber-2),var(--amber));box-shadow:0 0 6px rgba(244,165,43,.55)}
.mark.lg{width:54px;height:54px;border-radius:13px}
.mark.lg .pg{inset:9px;gap:4px}
.mark.lg .p{border-radius:4px}

/* ---------- nav ---------- */
.nav{position:sticky;top:0;z-index:50;
  background:rgba(8,9,11,.72);backdrop-filter:saturate(140%) blur(16px);
  border-bottom:1px solid var(--line-soft)}
.nav .wrap{display:flex;align-items:center;gap:14px;height:68px}
.brand{display:flex;align-items:center;gap:11px;font-weight:800;font-size:18px;letter-spacing:-.01em}
.nav .links{display:flex;align-items:center;gap:6px;margin-left:auto}
.nav .links a{padding:9px 14px;border-radius:10px;font-size:14.5px;font-weight:600;color:var(--dim);transition:.15s}
.nav .links a:hover{color:var(--text);background:var(--panel)}
.nav .links a.active{color:var(--text)}
.lang-btn{display:flex;align-items:center;gap:6px;padding:8px 13px;border-radius:10px;
  border:1px solid var(--line);font-size:13px;font-weight:700;color:var(--dim);transition:.15s;margin-left:6px}
.lang-btn:hover{color:var(--text);border-color:var(--dim-2)}
.nav-cta{padding:10px 18px;border-radius:11px;font-size:14px;font-weight:700;
  background:linear-gradient(165deg,var(--amber-2),var(--amber));color:#2a1c04;transition:.15s}
.nav-cta:hover{filter:brightness(1.05)}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:10px;padding:14px 22px;border-radius:13px;
  font-size:15px;font-weight:700;transition:.16s var(--ease)}
.btn-amber{background:linear-gradient(165deg,var(--amber-2),var(--amber));color:#2a1c04;
  box-shadow:0 10px 30px -10px rgba(244,165,43,.5)}
.btn-amber:hover{transform:translateY(-2px);box-shadow:0 16px 40px -12px rgba(244,165,43,.6)}
.btn-ghost{background:var(--panel);border:1px solid var(--line);color:var(--text)}
.btn-ghost:hover{border-color:var(--dim-2);background:var(--panel-2)}

/* store badges */
.stores{display:flex;flex-wrap:wrap;gap:14px}
.store{display:flex;align-items:center;gap:13px;padding:12px 20px 12px 17px;border-radius:14px;
  background:var(--panel);border:1px solid var(--line);transition:.16s var(--ease);min-width:200px}
.store:hover{transform:translateY(-2px);border-color:var(--dim-2);background:var(--panel-2)}
.store svg{width:27px;height:27px;flex:0 0 auto}
.store .st{display:flex;flex-direction:column;line-height:1.25}
.store .st small{font-size:11px;color:var(--dim);font-weight:600}
.store .st b{font-size:16px;font-weight:700}

/* ---------- footer ---------- */
.footer{border-top:1px solid var(--line-soft);background:var(--bg);margin-top:120px}
.footer .wrap{padding-top:64px;padding-bottom:48px;
  display:grid;grid-template-columns:1.6fr 1fr 1fr;gap:48px}
.footer .fbrand{display:flex;flex-direction:column;gap:16px;max-width:320px}
.footer .fbrand .brand{font-size:18px}
.footer .fbrand p{font-size:13.5px;color:var(--dim);line-height:1.6}
.footer .fcol h4{font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--dim-2);
  font-weight:700;margin-bottom:16px}
.footer .fcol a{display:block;font-size:14px;color:var(--dim);padding:6px 0;transition:.15s}
.footer .fcol a:hover{color:var(--text)}
.footer .bar{border-top:1px solid var(--line-soft)}
.footer .bar .wrap{display:flex;flex-wrap:wrap;gap:14px;align-items:center;justify-content:space-between;
  padding-top:24px;padding-bottom:40px}
.footer .bar small{font-size:12.5px;color:var(--dim-2)}

/* ---------- generic section heading ---------- */
.shead{text-align:center;max-width:720px;margin:0 auto 56px}
.shead .eyebrow{margin-bottom:16px;display:block}
.shead h2{font-size:clamp(30px,4vw,46px);font-weight:800;letter-spacing:-.02em;line-height:1.1}
.shead p{margin-top:18px;font-size:17px;color:var(--dim);line-height:1.65}

/* ---------- legal / doc pages ---------- */
.doc{padding:64px 0 40px}
.doc .wrap{max-width:820px}
.doc .doc-head{margin-bottom:48px;padding-bottom:32px;border-bottom:1px solid var(--line)}
.doc .doc-head h1{font-size:clamp(32px,5vw,48px);font-weight:800;letter-spacing:-.02em;line-height:1.1}
.doc .doc-head .meta{margin-top:18px;font-size:14px;color:var(--dim-2);display:flex;gap:18px;flex-wrap:wrap}
.doc h2{font-size:22px;font-weight:800;letter-spacing:-.01em;margin:44px 0 14px;scroll-margin-top:90px}
.doc h2 .n{color:var(--amber);font-weight:700;margin-right:10px;font-variant-numeric:tabular-nums}
.doc h3{font-size:16.5px;font-weight:700;margin:26px 0 10px}
.doc p{font-size:15.5px;color:#c5cad1;margin:12px 0;line-height:1.75}
.doc ul{margin:14px 0 14px 4px;padding:0;list-style:none;display:flex;flex-direction:column;gap:11px}
.doc ul li{position:relative;padding-left:26px;font-size:15px;color:#c5cad1;line-height:1.7}
.doc ul li::before{content:"";position:absolute;left:6px;top:11px;width:6px;height:6px;border-radius:2px;
  background:var(--amber)}
.doc a.inl{color:var(--amber-2);border-bottom:1px solid var(--amber-line);transition:.15s}
.doc a.inl:hover{color:var(--amber)}
.doc .callout{margin:24px 0;padding:20px 22px;border-radius:14px;background:var(--panel);
  border:1px solid var(--line);border-left:3px solid var(--amber)}
.doc .callout p{margin:0;font-size:14.5px;color:var(--dim)}
.doc .callout p strong{color:var(--text)}

/* table of contents */
.toc{position:sticky;top:90px;align-self:start}
.doc-layout{display:grid;grid-template-columns:1fr;gap:0}
.toc-list{display:flex;flex-direction:column;gap:2px}
.toc-list a{font-size:13.5px;color:var(--dim-2);padding:7px 12px;border-radius:8px;transition:.15s;border-left:2px solid transparent}
.toc-list a:hover{color:var(--text);background:var(--panel)}

/* ---------- fade-in on scroll ---------- */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ---------- responsive ---------- */
@media (max-width:880px){
  .nav .links{display:none}
  .footer .wrap{grid-template-columns:1fr 1fr;gap:36px}
  .footer .fbrand{grid-column:1/-1}
}
@media (max-width:560px){
  .wrap{padding:0 20px}
  .footer .wrap{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){
  .reveal{opacity:1;transform:none;transition:none}
  html{scroll-behavior:auto}
}