/* ===== 云集建模 · 空间智能 — 单页站点 ===== */
:root{
  --ink:#0D1117; --ink2:#151B24; --ink3:#1C2530; --line:#2A3543;
  --cyan:#2DD4BF; --cyand:#12A99B; --amber:#F4B740;
  --white:#F4F7FA; --gray:#B4BEC9; --mute:#76828F;
  --maxw:1200px; --nav-h:64px;
  --cn:"Microsoft YaHei","PingFang SC","Hiragino Sans GB",system-ui,sans-serif;
  --lat:"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--cn); background:var(--ink); color:var(--gray);
  line-height:1.7; -webkit-font-smoothing:antialiased; overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.lat{font-family:var(--lat)}

/* ---- kicker / section heads ---- */
.kicker{font-family:var(--lat);font-size:13px;font-weight:700;letter-spacing:3px;
  color:var(--cyan);text-transform:uppercase;margin-bottom:10px;display:flex;align-items:center;gap:10px}
.kicker::before{content:"";width:26px;height:3px;background:var(--cyan);border-radius:2px}
h2.title{font-size:34px;font-weight:800;color:var(--white);letter-spacing:.5px;line-height:1.25}
.lead{margin-top:14px;max-width:760px;color:var(--gray);font-size:16px}
.section{padding:96px 0;position:relative}
.section.alt{background:linear-gradient(180deg,#0b0f15,#0d1117)}

/* ---- reveal animation ---- */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .7s ease,transform .7s ease}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.08s}.reveal.d2{transition-delay:.16s}
.reveal.d3{transition-delay:.24s}.reveal.d4{transition-delay:.32s}

/* ===== NAV ===== */
.nav{position:fixed;top:0;left:0;right:0;height:var(--nav-h);z-index:50;
  display:flex;align-items:center;
  background:rgba(13,17,23,0);backdrop-filter:blur(0);transition:background .3s,box-shadow .3s,backdrop-filter .3s}
.nav.scrolled{background:rgba(13,17,23,.86);backdrop-filter:blur(12px);box-shadow:0 1px 0 var(--line)}
.nav .container{display:flex;align-items:center;justify-content:space-between;width:100%}
.brand{font-weight:800;color:var(--white);font-size:17px;letter-spacing:.5px}
.brand b{color:var(--cyan)}
.brand span{color:var(--mute);font-family:var(--lat);font-weight:600;font-size:14px}
.menu{display:flex;gap:30px;list-style:none}
.menu a{font-size:14.5px;color:var(--gray);position:relative;padding:6px 0;transition:color .2s}
.menu a:hover{color:var(--white)}
.menu a.active{color:var(--cyan)}
.menu a.active::after{content:"";position:absolute;left:0;right:0;bottom:-2px;height:2px;background:var(--cyan);border-radius:2px}
.burger{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:6px}
.burger span{width:24px;height:2px;background:var(--white);transition:.3s}

/* ===== HERO ===== */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;
  background:url(../assets/img/hero.jpg) center/cover no-repeat}
.hero::before{content:"";position:absolute;inset:0;
  background:linear-gradient(90deg,rgba(13,17,23,.94) 0%,rgba(13,17,23,.78) 42%,rgba(13,17,23,.4) 100%)}
.hero::after{content:"";position:absolute;inset:0;background:rgba(13,17,23,.32)}
.hero .container{position:relative;z-index:2}
.hero-tag{font-family:var(--lat);color:var(--cyan);font-weight:700;letter-spacing:2px;font-size:14px;margin-bottom:18px}
.hero h1{font-size:clamp(34px,5.4vw,60px);font-weight:800;color:var(--white);line-height:1.12;letter-spacing:1px}
.hero .sub{margin-top:20px;font-size:clamp(16px,2vw,20px);color:#d6dde4;max-width:620px}
.hero .pills{margin-top:22px;font-family:var(--lat);font-weight:700;letter-spacing:1px;color:var(--cyan);font-size:15px}
.hero .pills span{color:var(--mute);margin:0 10px}
.hero-cta{margin-top:38px;display:flex;gap:16px;flex-wrap:wrap}
.btn{display:inline-block;padding:14px 30px;border-radius:30px;font-size:15px;font-weight:700;
  transition:transform .2s,box-shadow .2s,background .2s,color .2s;cursor:pointer}
.btn-primary{background:var(--cyan);color:#06231f;box-shadow:0 8px 24px rgba(45,212,191,.28)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 30px rgba(45,212,191,.4)}
.btn-ghost{border:1px solid var(--line);color:var(--white)}
.btn-ghost:hover{border-color:var(--cyan);color:var(--cyan)}
.scroll-ind{position:absolute;bottom:26px;left:50%;transform:translateX(-50%);z-index:2;
  color:var(--mute);font-size:12px;letter-spacing:2px;text-align:center;animation:bob 2s infinite}
.scroll-ind .arrow{display:block;margin:6px auto 0;width:8px;height:8px;border-right:2px solid var(--cyan);
  border-bottom:2px solid var(--cyan);transform:rotate(45deg)}
@keyframes bob{0%,100%{transform:translate(-50%,0)}50%{transform:translate(-50%,7px)}}

/* ===== CORE TECH ===== */
.tech-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px;margin-top:48px;align-items:start}
.concept p{margin-bottom:16px;color:var(--gray);font-size:15.5px}
.concept .k{color:var(--cyan);font-weight:700}
.bullets{list-style:none;margin:6px 0 0}
.bullets li{position:relative;padding-left:20px;margin:9px 0;color:var(--gray);font-size:15px}
.bullets li::before{content:"";position:absolute;left:0;top:11px;width:7px;height:7px;border-radius:50%;background:var(--cyan)}
.result{margin-top:26px;border:1px solid var(--cyand);background:var(--ink2);border-radius:10px;
  padding:18px 22px;border-left:4px solid var(--amber)}
.result b{color:var(--amber)}
.result span{color:var(--white)}
/* architecture stack */
.arch{display:flex;flex-direction:column;gap:14px}
.arch .arch-cap{font-family:var(--lat);font-size:12px;letter-spacing:3px;color:var(--cyan);font-weight:700;margin-bottom:2px}
.arch .row{display:grid;gap:14px}
.arch .row.three{grid-template-columns:repeat(3,1fr)}
.arch .cell{background:var(--ink3);border:1px solid var(--line);border-top:3px solid var(--cyan);
  border-radius:9px;padding:18px 8px;text-align:center;color:var(--white);font-weight:700;font-size:15px}
.arch .cell.wide{border-top:1px solid var(--line)}
.arch .cell.hi{background:#10303a;border:1px solid var(--cyan);border-top:1px solid var(--cyan);color:var(--cyan)}

/* four modules */
.modules{display:grid;grid-template-columns:repeat(2,1fr);gap:22px;margin-top:64px}
.mod{background:var(--ink2);border:1px solid var(--line);border-top:3px solid var(--cyan);
  border-radius:12px;padding:26px 26px 28px;transition:transform .25s,border-color .25s,box-shadow .25s}
.mod:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(0,0,0,.35);border-color:var(--cyand)}
.mod .num{font-family:var(--lat);font-size:26px;font-weight:800;color:var(--cyan)}
.mod h4{display:inline-block;margin-left:12px;color:var(--white);font-size:19px;font-weight:800;vertical-align:2px}
.mod p{margin-top:12px;color:var(--gray);font-size:14.5px}

/* ===== FEATURES ===== */
.feats{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;margin-top:48px}
.feat{background:var(--ink2);border:1px solid var(--line);border-radius:14px;padding:30px 26px;
  transition:transform .25s,border-color .25s,box-shadow .25s}
.feat:hover{transform:translateY(-4px);border-color:var(--cyan);box-shadow:0 16px 38px rgba(0,0,0,.4)}
.feat-ic{width:52px;height:52px;border-radius:13px;display:flex;align-items:center;justify-content:center;
  background:rgba(45,212,191,.12);border:1px solid rgba(45,212,191,.35);margin-bottom:18px}
.feat-ic svg{width:26px;height:26px;stroke:var(--cyan);fill:none;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.feat h4{color:var(--white);font-size:18px;font-weight:800;margin-bottom:10px;line-height:1.3}
.feat p{color:var(--gray);font-size:14.5px;line-height:1.78}
.feat .badge{display:inline-block;margin-top:14px;font-family:var(--lat);font-size:12px;font-weight:700;
  color:var(--amber);border:1px solid rgba(244,183,64,.4);border-radius:20px;padding:4px 13px;letter-spacing:.3px}

/* ===== RECONSTRUCTION PIPELINE ===== */
/* reconstruction sub-part (within Features) */
.subpart{margin-top:50px;padding-top:36px;border-top:1px solid var(--line)}
.subpart-tag{font-family:var(--lat);font-size:12px;letter-spacing:2px;color:var(--cyan);font-weight:700;text-transform:uppercase}
.subpart-head h3{color:var(--white);font-size:22px;font-weight:800;margin:9px 0 8px}
.subpart-head p{color:var(--gray);font-size:14.5px;max-width:840px}
.subpart .pipeline{margin-top:34px}

.pipeline{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:48px}
.step{position:relative;background:var(--ink2);border:1px solid var(--line);border-radius:14px;
  overflow:hidden;transition:transform .25s,border-color .25s,box-shadow .25s}
.step:hover{transform:translateY(-4px);border-color:var(--cyan);box-shadow:0 16px 38px rgba(0,0,0,.4)}
.step-img{aspect-ratio:1/1;background:#05070a;display:flex;align-items:center;justify-content:center}
.step-img img{width:100%;height:100%;object-fit:contain}
.step .body{padding:16px 18px 20px}
.step-no{font-size:12px;font-weight:700;letter-spacing:2px;color:var(--cyan)}
.step h4{color:var(--white);font-size:16px;font-weight:800;margin:5px 0 7px;line-height:1.3}
.step p{color:var(--gray);font-size:13px;line-height:1.62}
.pipeline .step:not(:last-child)::after{content:"";position:absolute;top:28%;right:-13px;z-index:4;
  width:11px;height:11px;border-top:2px solid var(--cyan);border-right:2px solid var(--cyan);transform:rotate(45deg)}

/* ===== CASES ===== */
.cases{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-top:48px}
.case{background:var(--ink2);border:1px solid var(--line);border-radius:14px;overflow:hidden;
  transition:transform .25s,border-color .25s,box-shadow .25s}
.case:hover{transform:translateY(-5px);border-color:var(--cyan);box-shadow:0 16px 40px rgba(0,0,0,.4)}
.case .ph{aspect-ratio:16/10;overflow:hidden;background:#05070a}
.case .ph img{width:100%;height:100%;object-fit:cover;transition:transform .5s}
.case:hover .ph img{transform:scale(1.06)}
.case .body{padding:20px 22px 24px}
.case .tagline{font-family:var(--lat);font-size:11px;letter-spacing:2px;color:var(--cyan);font-weight:700;text-transform:uppercase}
.case h4{color:var(--white);font-size:18px;font-weight:800;margin:8px 0 8px}
.case p{color:var(--gray);font-size:14px}

/* ===== METRICS ===== */
#metrics{background:linear-gradient(180deg,#0b0f15,#0d1117)}
.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin-top:48px}
.stat{background:var(--ink2);border:1px solid var(--line);border-top:3px solid var(--cyan);
  border-radius:14px;padding:34px 22px;text-align:center}
.stat .big{font-family:var(--lat);font-size:48px;font-weight:800;line-height:1}
.stat .big.amber{color:var(--amber)}.stat .big.cyan{color:var(--cyan)}
.stat .unit{margin-top:10px;color:var(--white);font-weight:700;font-family:var(--lat);font-size:14px}
.stat .desc{margin-top:12px;color:var(--gray);font-size:13.5px}
.features{margin-top:32px;background:var(--ink2);border:1px solid var(--line);border-left:4px solid var(--cyan);
  border-radius:12px;padding:28px 30px}
.features h4{color:var(--cyan);font-size:18px;margin-bottom:18px}
.features ul{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:12px 36px}
.features li{position:relative;padding-left:22px;color:var(--gray);font-size:14.5px}
.features li::before{content:"";position:absolute;left:0;top:9px;width:7px;height:7px;border-radius:50%;background:var(--cyan)}

/* ===== CERT ===== */
.cert-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:20px;margin-top:48px}
.cert{background:#fff;border:1px solid var(--line);border-radius:10px;overflow:hidden;
  display:flex;align-items:center;justify-content:center;transition:transform .25s,box-shadow .25s}
.cert:hover{transform:translateY(-4px);box-shadow:0 14px 34px rgba(0,0,0,.4)}
.cert.soft{grid-row:span 2;background:#0a1018}
.cert img{width:100%;height:100%;object-fit:cover}
.cert.soft img{object-fit:cover}

/* ===== ABOUT ===== */
.about-wrap{max-width:900px;margin:0 auto;text-align:center}
.kicker.center{justify-content:center}
.about-one{margin:22px auto 0;font-size:19px;line-height:1.95;color:var(--gray);max-width:840px}
.about-tags{margin-top:32px;display:flex;gap:12px;flex-wrap:wrap;justify-content:center}
.about-tags span{border:1px solid var(--line);background:var(--ink2);color:var(--white);
  border-radius:30px;padding:9px 20px;font-size:14px}
.about-tags span::before{content:"";display:inline-block;width:6px;height:6px;border-radius:50%;
  background:var(--cyan);margin-right:9px;vertical-align:1px}

/* ===== FOOTER / CONTACT ===== */
.foot{position:relative;background:url(../assets/img/hero.jpg) center/cover;padding:90px 0 40px;text-align:center}
.foot::before{content:"";position:absolute;inset:0;background:rgba(13,17,23,.9)}
.foot .container{position:relative;z-index:2}
.foot .yunji{font-family:var(--lat);letter-spacing:10px;color:var(--cyan);font-weight:700;font-size:20px}
.foot h3{color:var(--white);font-size:clamp(26px,4vw,40px);font-weight:800;margin:14px 0}
.foot .rule{width:54px;height:4px;background:var(--cyan);border-radius:3px;margin:18px auto}
.foot .sub{color:var(--gray);font-size:16px}
.foot .org{color:var(--white);font-weight:700;margin-top:30px;font-size:16px}
.foot .copy{color:var(--mute);font-size:12.5px;margin-top:10px}
.foot .links{margin-top:24px;display:flex;gap:24px;justify-content:center;flex-wrap:wrap}
.foot .links a{color:var(--gray);font-size:13.5px}
.foot .links a:hover{color:var(--cyan)}

/* ===== 3D DEMO MODAL ===== */
.demo-modal{position:fixed;inset:0;z-index:300;background:rgba(5,8,12,.94);display:none;flex-direction:column}
.demo-modal.open{display:flex}
.demo-bar{display:flex;align-items:center;justify-content:space-between;padding:11px 18px;color:#f4f7fa;font-weight:700;background:#0d1117;border-bottom:1px solid #2a3543}
.demo-bar button{background:none;border:0;color:#9aa7b4;font-size:26px;line-height:1;cursor:pointer;padding:0 6px}
.demo-bar button:hover{color:#fff}
.demo-modal iframe{flex:1;width:100%;border:0;background:#0d1117}

/* ===== RESPONSIVE ===== */
@media(max-width:900px){
  .tech-grid{grid-template-columns:1fr;gap:36px}
  .feats{grid-template-columns:repeat(2,1fr)}
  .pipeline{grid-template-columns:repeat(2,1fr)}
  .pipeline .step::after{display:none}
  .cases{grid-template-columns:repeat(2,1fr)}
  .modules{grid-template-columns:1fr}
  .stats{grid-template-columns:1fr}
  .features ul{grid-template-columns:1fr}
  .cert-grid{grid-template-columns:1fr 1fr}
  .cert.soft{grid-row:auto;grid-column:span 2;aspect-ratio:16/9}
}
@media(max-width:720px){
  .section{padding:64px 0}
  h2.title{font-size:27px}
  .menu{position:fixed;inset:var(--nav-h) 0 auto 0;flex-direction:column;gap:0;
    background:rgba(13,17,23,.97);backdrop-filter:blur(12px);border-bottom:1px solid var(--line);
    transform:translateY(-130%);transition:transform .35s;padding:8px 0}
  .menu.open{transform:none}
  .menu li{border-bottom:1px solid var(--line)}
  .menu a{display:block;padding:15px 24px}
  .menu a.active::after{display:none}
  .feats{grid-template-columns:1fr}
  .pipeline{grid-template-columns:1fr}
  .burger{display:flex}
  .burger.open span:nth-child(1){transform:translateY(7px) rotate(45deg)}
  .burger.open span:nth-child(2){opacity:0}
  .burger.open span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
  .cases{grid-template-columns:1fr}
  .cert-grid{grid-template-columns:1fr}
  .cert.soft{grid-column:auto}
}