/* ============================================================
   rev3.css — 共享设计系统（审美专家五 skill 共审：taste-skill +
   impeccable + canvas-design + gpt-taste + redesign-skill）
   深色 #0F0E10 · plum 灰阶过渡 · 洋红 #D81B60 单 accent ·
   Noto Serif SC 展示 / Noto Sans SC 正文 · 细噪点 · 语义结构
   ============================================================ */
:root{
  --bg:#0F0E10;
  --bg2:#141217;
  --plum1:#1A141D;
  --plum2:#2A1A24;
  --plum3:#3D2433;
  --mg:#D81B60;          /* single accent, HSL S=77.7% (<80% redesign OK) */
  --mg-soft:#CE2A63;
  --ink:#ECE7E3;
  --mut:#9A8F95;
  --line:rgba(216,27,96,.16);
  --line2:rgba(236,231,227,.08);
  --maxw:1240px;
  --z-nav:100;
  --z-grain:50;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:"Noto Sans SC",system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
::selection{background:var(--mg);color:#fff}
a{color:inherit;text-decoration:none}
:focus-visible{outline:2px solid var(--mg);outline-offset:3px;border-radius:2px}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-thumb{background:var(--plum3);border-radius:6px}
::-webkit-scrollbar-track{background:var(--bg)}
/* grain overlay (redesign: break flatness) */
body::after{
  content:"";position:fixed;inset:0;pointer-events:none;z-index:var(--z-grain);opacity:.035;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mix-blend-mode:overlay;
}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 28px}
/* nav: solid minimal split (no glass, per impeccable) */
nav{
  position:fixed;top:0;left:0;right:0;z-index:var(--z-nav);
  background:rgba(15,14,16,.82);
  border-bottom:1px solid var(--line2);
}
.nav-in{display:flex;align-items:center;justify-content:space-between;height:64px}
.brand{font-family:"Noto Serif SC",serif;font-weight:700;letter-spacing:.02em;font-size:1.02rem}
.brand .dot{color:var(--mg)}
.nav-links{display:flex;gap:30px;align-items:center;font-size:.9rem;color:var(--mut)}
.nav-links a{transition:color .25s ease}
.nav-links a:hover{color:var(--ink)}
.nav-cta{
  border:1px solid var(--line);border-radius:3px;padding:8px 16px;color:var(--ink);
  transition:border-color .25s ease,color .25s ease;
}
.nav-cta:hover{border-color:var(--mg);color:var(--mg)}
/* hero: editorial split, 2-3 lines, wide container */
.hero{padding:160px 0 110px;position:relative}
.hero::before{
  content:"";position:absolute;top:-10%;right:-5%;width:60vw;height:60vw;max-width:680px;max-height:680px;
  background:radial-gradient(circle at center,rgba(216,27,96,.10),transparent 62%);
  pointer-events:none;z-index:0;
}
.hero .wrap{position:relative;z-index:1}
.hero h1{
  font-family:"Noto Serif SC",serif;font-weight:700;
  font-size:clamp(2.6rem,5.4vw,4.6rem);line-height:1.08;letter-spacing:-.01em;
  max-width:18ch;margin-bottom:28px;
}
.hero h1 .ac{color:var(--mg)}
.hero p.lede{max-width:60ch;color:var(--mut);font-size:1.08rem;margin-bottom:38px}
.hero-actions{display:flex;gap:16px;flex-wrap:wrap;align-items:center}
.btn{
  display:inline-flex;align-items:center;gap:8px;border-radius:3px;
  padding:14px 26px;font-weight:600;font-size:.98rem;cursor:pointer;
  transition:transform .2s ease,background .25s ease,border-color .25s ease;
}
.btn:active{transform:translateY(1px) scale(.99)}
.btn-primary{background:var(--mg);color:#fff;border:1px solid var(--mg)}
.btn-primary:hover{background:var(--mg-soft)}
.btn-ghost{background:transparent;color:var(--ink);border:1px solid var(--line2)}
.btn-ghost:hover{border-color:var(--mg);color:var(--mg)}
/* section rhythm (redesign: huge padding) */
section{padding:clamp(72px,11vw,140px) 0}
.sec-head{max-width:62ch;margin-bottom:54px}
.sec-head h2{
  font-family:"Noto Serif SC",serif;font-weight:600;font-size:clamp(1.7rem,3.2vw,2.5rem);
  line-height:1.15;letter-spacing:-.005em;margin-bottom:14px;
}
.sec-head p{color:var(--mut);font-size:1.02rem}
/* bento: gapless grid-flow-dense (gpt-taste), asymmetric, 3 cards */
.bento{display:grid;grid-template-columns:repeat(3,1fr);grid-auto-flow:dense;gap:18px}
.bcard{
  background:var(--bg2);border:1px solid var(--line2);border-radius:3px;padding:34px;
  display:flex;flex-direction:column;gap:12px;min-height:200px;
  transition:border-color .3s ease,transform .3s ease;
}
.bcard:hover{border-color:var(--line);transform:translateY(-3px)}
.bcard.wide{grid-column:span 2}
.bcard h3{font-family:"Noto Serif SC",serif;font-weight:600;font-size:1.32rem}
.bcard p{color:var(--mut);font-size:.97rem}
.bcard .tag{margin-top:auto;font-size:.82rem;color:var(--mg);letter-spacing:.04em}
/* video grid: 2x2, video is the hero asset */
.vgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.vcard{
  background:var(--bg2);border:1px solid var(--line2);border-radius:3px;overflow:hidden;
  display:flex;flex-direction:column;
  transition:border-color .3s ease;
}
.vcard:hover{border-color:var(--line)}
.vframe{position:relative;aspect-ratio:16/9;background:#08070a;overflow:hidden}
.vframe video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:block;z-index:1}
.vframe .ph{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:var(--mut);font-size:.85rem;z-index:0}
.cap{padding:18px 20px;display:flex;justify-content:space-between;align-items:baseline;gap:12px}
.cap b{font-family:"Noto Serif SC",serif;font-weight:600;color:var(--ink);font-size:.98rem}
.cap span{color:var(--mut);font-size:.85rem;white-space:nowrap}
/* plum scale band: material/color system (canvas-design) */
.scale{display:grid;grid-template-columns:repeat(5,1fr);gap:0;border:1px solid var(--line2);border-radius:3px;overflow:hidden}
.scale div{height:84px;display:flex;align-items:flex-end;justify-content:center;padding-bottom:10px;font-size:.72rem;color:var(--mut)}
.scale .s0{background:var(--bg)}.scale .s1{background:var(--plum1)}
.scale .s2{background:var(--plum2)}.scale .s3{background:var(--plum3)}
.scale .s4{background:var(--mg);color:#fff}
/* CTA: massive high-contrast (gpt-taste Action) */
.cta{text-align:center;position:relative}
.cta::before{content:"";position:absolute;inset:0;background:radial-gradient(circle at 50% 40%,rgba(216,27,96,.12),transparent 60%);pointer-events:none}
.cta .wrap{position:relative;z-index:1}
.cta h2{font-family:"Noto Serif SC",serif;font-weight:700;font-size:clamp(2rem,4.4vw,3.4rem);line-height:1.12;margin-bottom:20px}
.cta p{color:var(--mut);max-width:52ch;margin:0 auto 34px}
/* footer */
footer{border-top:1px solid var(--line2);padding:54px 0;color:var(--mut);font-size:.88rem}
.foot-in{display:flex;justify-content:space-between;flex-wrap:wrap;gap:24px;align-items:center}
.foot-links{display:flex;gap:24px;flex-wrap:wrap}
.foot-links a:hover{color:var(--ink)}
/* reveal (IO fallback; GSAP enhances) */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .8s ease,transform .8s ease}
.reveal.in{opacity:1;transform:none}
/* loading skeleton for video */
.vframe[data-loading="1"]::after{content:"";position:absolute;inset:0;z-index:2;background:linear-gradient(100deg,var(--bg2) 30%,var(--plum2) 50%,var(--bg2) 70%);background-size:200% 100%;animation:sk 1.4s infinite}
@keyframes sk{to{background-position:-200% 0}}
@media (max-width:820px){
  .bento{grid-template-columns:1fr}.bcard.wide{grid-column:span 1}
  .vgrid{grid-template-columns:1fr}
  .nav-links{display:none}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important;scroll-behavior:auto!important}
  .reveal{opacity:1!important;transform:none!important}
}