/* core: tokens / reset / nav / shared flip / shared scaffolding / global components */
:root {
  --bg:#050505; --card:#0e0d0b; --ink:#f5f2ea; --muted:#9a958a; --faint:#5f5b53;
  --gold:#ffb02e; --gold-deep:#e8a33d; --gold-soft:rgba(255,176,46,.12);
  --red:#e5484d; --line:rgba(245,242,234,.1); --tile-line:rgba(0,0,0,.72);
  --serif:"Noto Serif SC","Songti SC",serif;
  --sans:"Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --mono:"JetBrains Mono","SF Mono",Consolas,monospace;
  --ease-out:cubic-bezier(.22,1,.36,1); --ease-back:cubic-bezier(.34,1.3,.64,1);
}
* { box-sizing:border-box; }
html { scroll-behavior:smooth; }
body { margin:0; color:var(--ink); background:var(--bg); font-family:var(--sans); -webkit-font-smoothing:antialiased; overflow-x:hidden; user-select:none; -webkit-user-select:none; }
input, textarea { user-select:text; -webkit-user-select:text; }
button,input { font:inherit; }
button { cursor:pointer; }

/* 顶栏 */
#nav { position:fixed; z-index:50; top:0; left:0; right:0; display:flex; align-items:center; justify-content:space-between; gap:16px; padding:14px 32px; background:rgba(5,5,5,.66); backdrop-filter:blur(16px); border-bottom:1px solid var(--line); }
.wordmark { display:flex; align-items:baseline; gap:10px; text-decoration:none; }
.wordmark .pi { font-family:var(--mono); font-weight:700; font-size:1.15rem; color:var(--gold); }
.wordmark .pi-sub { font-size:.72em; }
.wordmark .cn { font-size:.86rem; color:var(--muted); letter-spacing:.12em; }
.nav-clock { display:flex; align-items:center; gap:3px; }
.nav-cta { display:flex; gap:8px; }
.pill { border:1px solid var(--line); border-radius:999px; padding:8px 16px; font-size:.85rem; color:var(--muted); background:transparent; transition:color 220ms var(--ease-out),border-color 220ms var(--ease-out),transform 220ms var(--ease-out); }
.pill:hover { color:var(--gold); border-color:var(--gold-deep); transform:translateY(-1px); }
.pill:focus-visible,.btn:focus-visible { outline:2px solid var(--gold); outline-offset:3px; }
.pill:active,.btn:active { transform:scale(.98); }
.pill.dark { color:#0c0a06; background:var(--gold); border-color:var(--gold); font-weight:600; }
.pill.dark:hover { color:#0c0a06; background:var(--gold-deep); }
.flip-mini { position:relative; width:20px; height:28px; border:1px solid rgba(255,183,48,.16); border-radius:5px; overflow:hidden; perspective:160px; font-family:var(--mono); font-size:.95rem; font-weight:700; color:var(--gold); opacity:.8; }
.flip-mini::after { content:""; position:absolute; z-index:3; top:50%; left:0; right:0; height:1px; background:var(--tile-line); }
.flip-mini-colon { color:var(--faint); font-family:var(--mono); font-size:.8rem; padding:0 1px; animation:pulse 1s ease-in-out infinite; }

/* 分体翻牌共享实现 */
.half { position:absolute; inset:0; display:grid; place-items:center; backface-visibility:hidden; }
.half.top,.half.flap-front { background:linear-gradient(180deg,#26231d,#1c1a15); clip-path:inset(0 0 50% 0); }
.half.bottom,.half.flap-back { background:linear-gradient(180deg,#161411,#191712); clip-path:inset(50% 0 0 0); }
.half.flap-front { transform-origin:center bottom; z-index:2; visibility:hidden; transition:transform 200ms cubic-bezier(.64,0,.78,0),filter 200ms linear; }
.half.flap-back { transform-origin:center top; transform:rotateX(90deg); filter:brightness(.45); z-index:2; visibility:hidden; transition:transform 240ms cubic-bezier(.34,1.56,.64,1),filter 240ms linear; }
.flipping .half.flap-front { visibility:visible; transform:rotateX(-90deg); filter:brightness(.45); }
.flipping .half.flap-back { visibility:visible; transform:rotateX(0deg); filter:brightness(1); transition-delay:170ms; }
.flip-number { display:flex; min-height:74px; gap:6px; margin:16px 0 4px; overflow:hidden; }
.flip-tile { position:relative; min-width:32px; height:66px; display:grid; place-items:center; padding:0 6px; border:1px solid rgba(255,176,46,.12); border-radius:8px; color:var(--ink); font-family:var(--mono); font-size:2.2rem; font-weight:700; overflow:hidden; perspective:400px; box-shadow:inset 0 1px 0 rgba(255,255,255,.05); }
.flip-tile::after { content:""; position:absolute; z-index:3; top:50%; left:0; right:0; height:1px; background:var(--tile-line); opacity:.65; }
.flip-tile.separator { min-width:10px; padding:0; border:0; color:var(--faint); }
.flip-tile.separator,.flip-tile.separator .half { background:transparent; }
.compact { gap:4px; }
.compact .flip-tile { min-width:30px; height:60px; padding:0 5px; border-radius:6px; }

/* 区块共享脚手架 */
.screen { position:relative; z-index:2; background:var(--bg); }
.eyebrow { margin:0 0 22px; font-family:var(--mono); font-size:.75rem; letter-spacing:.22em; color:var(--gold-deep); }
h1,h2 { font-family:var(--serif); font-weight:700; }
h1 { margin:0; font-size:clamp(3.4rem,7.6vw,7.6rem); line-height:1.06; }
h2 { margin:0 0 14px; font-size:clamp(2rem,4.6vw,3.9rem); line-height:1.16; }
.comma { color:var(--gold); }
.inner { width:min(1180px,calc(100% - 48px)); margin:0 auto; padding:clamp(96px,14vh,160px) 0 clamp(64px,9vh,110px); }
.lead { max-width:620px; color:var(--muted); line-height:1.8; margin:0 0 clamp(40px,6vh,64px); }
.btn { border:1px solid var(--gold); border-radius:999px; padding:14px 30px; font-size:1rem; font-weight:600; color:#0c0a06; background:var(--gold); transition:background 220ms var(--ease-out),transform 220ms var(--ease-out),box-shadow 220ms var(--ease-out); }
.btn:hover { background:var(--gold-deep); transform:translateY(-2px); box-shadow:0 14px 34px rgba(255,176,46,.22); }
.btn.ghost { color:#bbb5aa; background:transparent; border-color:var(--line); font-weight:500; }
.btn.ghost:hover { color:var(--gold); border-color:var(--gold-deep); background:transparent; box-shadow:none; }
.btn.small { padding:10px 22px; font-size:.9rem; }

/* 弹窗与提示 */
.contact-dialog { position:fixed; width:min(400px,calc(100% - 34px)); padding:26px; border:1px solid var(--line); border-radius:16px; background:var(--card); color:var(--ink); box-shadow:0 40px 130px rgba(0,0,0,.7); }
.contact-dialog::backdrop { background:rgba(0,0,0,.62); backdrop-filter:blur(8px); }
.contact-dialog img { width:100%; border-radius:12px; }
.contact-dialog h2 { margin:16px 0 6px; font-size:1.4rem; }
.contact-dialog p { margin:0; color:var(--muted); font-size:.9rem; }
.dialog-close { position:absolute; top:12px; right:12px; width:32px; height:32px; border:1px solid var(--line); border-radius:50%; color:var(--muted); background:var(--bg); transition:color 200ms var(--ease-out),border-color 200ms var(--ease-out),transform 100ms var(--ease-out); }
.dialog-close:hover { color:var(--gold); border-color:var(--gold-deep); }
.dialog-close:focus-visible { outline:2px solid var(--gold); outline-offset:3px; }
.dialog-close:active { transform:scale(.96); }
.toast { position:fixed; left:50%; bottom:26px; z-index:60; transform:translate(-50%,24px); opacity:0; padding:11px 18px; border:1px solid var(--line); border-radius:999px; color:var(--ink); background:#171512; transition:200ms var(--ease-out); pointer-events:none; }
.toast.show { transform:translate(-50%,0); opacity:1; }

/* reveal */
.reveal { opacity:0; transform:translateY(26px); transition:opacity 520ms var(--ease-out),transform 520ms var(--ease-out); }
.reveal.in { opacity:1; transform:none; }

@keyframes pulse { 50% { opacity:.25; } }

@media (max-width:640px) {
  #nav { padding:12px 16px; }
  .wordmark .cn { display:none; }
  .nav-cta .pill:not(.dark) { display:none; }
  .pill { padding:7px 12px; font-size:.78rem; }
  h1 { font-size:3.2rem; }
  .compact .flip-tile { min-width:25px; height:52px; }
  .flip-tile { min-width:28px; height:58px; font-size:1.9rem; }
}
@media (prefers-reduced-motion:reduce) {
  *,*::before,*::after { animation-duration:1ms!important; transition-duration:1ms!important; transition-delay:0ms!important; scroll-behavior:auto!important; }
}