:root{
  --bg:#06090f;
  --bg-2:#0a0f18;
  --panel:#0d1422;
  --panel-2:#111a2c;
  --line:rgba(99,179,237,.14);
  --txt:#dbe7f5;
  --muted:#8aa0bb;
  --cyan:#22d3ee;
  --blue:#3b82f6;
  --violet:#8b5cf6;
  --grad:linear-gradient(120deg,#22d3ee,#3b82f6 55%,#8b5cf6);
  --radius:14px;
  --maxw:1180px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Inter","PingFang SC","Microsoft YaHei",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  background:var(--bg);color:var(--txt);line-height:1.7;font-size:16px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--cyan);text-decoration:none}
img{max-width:100%}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* grid backdrop */
.bg-grid{position:fixed;inset:0;z-index:-2;
  background-image:linear-gradient(rgba(59,130,246,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(59,130,246,.05) 1px,transparent 1px);
  background-size:48px 48px;}
.bg-glow{position:fixed;z-index:-1;width:720px;height:720px;border-radius:50%;
  filter:blur(140px);opacity:.16;pointer-events:none}
.bg-glow.g1{top:-220px;left:-160px;background:#3b82f6}
.bg-glow.g2{top:30%;right:-260px;background:#8b5cf6}

/* nav */
header.nav{position:sticky;top:0;z-index:50;backdrop-filter:blur(14px);
  background:rgba(6,9,15,.78);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:1.25rem;color:var(--txt);letter-spacing:.5px}
.logo .mark{width:30px;height:30px;border-radius:8px;background:var(--grad);
  display:grid;place-items:center;font-size:.85rem;color:#fff;font-weight:900}
.logo em{font-style:normal;background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.logo img.logo-img{height:36px;width:auto;display:block}
footer .logo img.logo-img{height:32px}
nav.menu{display:flex;align-items:center;gap:26px}
nav.menu a{color:var(--muted);font-size:.95rem;transition:color .2s}
nav.menu a:hover,nav.menu a.active{color:var(--txt)}
/* dropdown submenus */
.has-sub{position:relative}
.has-sub>a .caret{font-size:.65em;margin-left:4px;opacity:.7;display:inline-block;transition:transform .2s}
.submenu{position:absolute;top:100%;left:50%;transform:translateX(-50%);min-width:215px;
  background:rgba(8,12,20,.97);border:1px solid var(--line);border-radius:12px;
  padding:10px 8px;display:none;flex-direction:column;gap:2px;
  box-shadow:0 14px 40px rgba(0,0,0,.45)}
.submenu a{display:block;padding:8px 14px;border-radius:8px;font-size:.88rem;white-space:nowrap}
.submenu a:hover{background:rgba(34,211,238,.08);color:var(--txt)}
@media(min-width:641px){
  .has-sub::after{content:'';position:absolute;top:100%;left:0;right:0;height:16px}
  .has-sub:hover .submenu,.has-sub:focus-within .submenu{display:flex}
  .has-sub:hover>a .caret{transform:rotate(180deg)}
}
.lang-switch{border:1px solid var(--line);border-radius:8px;padding:5px 12px;font-size:.85rem;color:var(--cyan)}
.lang-switch:hover{border-color:var(--cyan)}
.nav-toggle{display:none;background:none;border:1px solid var(--line);color:var(--txt);
  border-radius:8px;padding:6px 10px;font-size:1.1rem;cursor:pointer}

/* hero */
.hero{padding:96px 0 80px;position:relative;overflow:hidden}
.hero .eyebrow{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);
  border-radius:999px;padding:6px 16px;font-size:.82rem;color:var(--cyan);
  background:rgba(34,211,238,.06);margin-bottom:26px}
.hero .eyebrow::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--cyan);
  box-shadow:0 0 10px var(--cyan)}
.hero h1{font-size:clamp(2.1rem,5vw,3.4rem);line-height:1.2;font-weight:800;max-width:840px}
.hero h1 .grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p.lead{margin-top:22px;font-size:1.12rem;color:var(--muted);max-width:720px}
.hero .cta-row{margin-top:36px;display:flex;gap:16px;flex-wrap:wrap}
.btn{display:inline-block;padding:13px 30px;border-radius:10px;font-weight:600;font-size:.98rem;transition:transform .15s,box-shadow .2s}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--grad);color:#fff;box-shadow:0 8px 30px rgba(59,130,246,.35)}
.btn-ghost{border:1px solid var(--line);color:var(--txt);background:rgba(255,255,255,.03)}
.btn-ghost:hover{border-color:var(--cyan)}

/* stats */
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-top:64px}
.stat{border:1px solid var(--line);border-radius:var(--radius);padding:22px 20px;
  background:linear-gradient(160deg,var(--panel),transparent)}
.stat .num{font-size:1.9rem;font-weight:800;background:var(--grad);
  -webkit-background-clip:text;background-clip:text;color:transparent}
.stat .lbl{color:var(--muted);font-size:.88rem;margin-top:4px}

/* sections */
section{padding:72px 0}
.sec-head{margin-bottom:44px;max-width:760px}
.sec-head .tag{color:var(--cyan);font-size:.85rem;letter-spacing:2px;text-transform:uppercase;font-weight:700}
.sec-head h2{font-size:clamp(1.6rem,3.4vw,2.3rem);font-weight:800;margin-top:10px}
.sec-head p{color:var(--muted);margin-top:12px}

.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:22px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}

.card{border:1px solid var(--line);border-radius:var(--radius);padding:28px 26px;
  background:linear-gradient(165deg,var(--panel) 0%,rgba(13,20,34,.4) 100%);
  position:relative;overflow:hidden;transition:border-color .25s,transform .2s}
.card:hover{border-color:rgba(34,211,238,.45);transform:translateY(-3px)}
.card::before{content:"";position:absolute;top:0;left:0;right:0;height:2px;
  background:var(--grad);opacity:0;transition:opacity .25s}
.card:hover::before{opacity:1}
.card .icon{width:44px;height:44px;border-radius:11px;background:rgba(34,211,238,.1);
  border:1px solid rgba(34,211,238,.25);display:grid;place-items:center;font-size:1.3rem;margin-bottom:18px}
.card h3{font-size:1.15rem;font-weight:700;margin-bottom:10px}
.card p{color:var(--muted);font-size:.93rem}
.card ul{list-style:none;margin-top:12px}
.card ul li{color:var(--muted);font-size:.9rem;padding:4px 0 4px 20px;position:relative}
.card ul li::before{content:"▸";position:absolute;left:0;color:var(--cyan)}
.card .pill{display:inline-block;font-size:.74rem;border:1px solid var(--line);
  border-radius:999px;padding:2px 10px;color:var(--cyan);margin:0 6px 6px 0;background:rgba(34,211,238,.05)}

/* alt panel section */
.panel-band{background:linear-gradient(180deg,transparent,rgba(13,20,34,.7) 18%,rgba(13,20,34,.7) 82%,transparent)}

/* case rows */
.case{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;
  padding:44px 0;border-bottom:1px solid var(--line)}
.case:last-child{border-bottom:none}
.case .vis{border:1px solid var(--line);border-radius:var(--radius);min-height:230px;
  background:radial-gradient(circle at 30% 30%,rgba(59,130,246,.18),transparent 60%),var(--panel-2);
  display:grid;place-items:center;color:var(--muted);font-size:.9rem;position:relative;overflow:hidden}
.case .vis .big{font-size:2.6rem;font-weight:900;background:var(--grad);
  -webkit-background-clip:text;background-clip:text;color:transparent}
.case h3{font-size:1.35rem;font-weight:800}
.case .industry{color:var(--cyan);font-size:.84rem;letter-spacing:1.5px;text-transform:uppercase;font-weight:700}
.case p{color:var(--muted);margin-top:12px;font-size:.95rem}
.case .metrics{display:flex;gap:26px;margin-top:18px;flex-wrap:wrap}
.case .metrics div b{display:block;font-size:1.4rem;background:var(--grad);
  -webkit-background-clip:text;background-clip:text;color:transparent}
.case .metrics div span{font-size:.8rem;color:var(--muted)}

/* case images */
.case .vis{padding:0}
.case .vis img{width:100%;height:100%;min-height:230px;object-fit:cover;display:block}
.vis-note{font-size:.74rem;color:var(--muted);text-align:center;margin-top:8px;opacity:.7}

/* logo wall */
.logo-wall{display:grid;grid-template-columns:repeat(6,1fr);gap:14px}
.logo-cell{background:#f5f8fc;border-radius:10px;display:grid;place-items:center;
  padding:10px 16px;height:68px;border:1px solid var(--line);
  filter:grayscale(.25);opacity:.92;transition:filter .25s,opacity .25s,transform .2s}
.logo-cell:hover{filter:none;opacity:1;transform:translateY(-2px)}
.logo-cell img{max-height:42px;max-width:100%;object-fit:contain}
/* homepage promo video */
.promo-video{margin:-20px auto 0;max-width:980px;padding:0 24px}
.promo-video video{width:100%;display:block;border-radius:18px;border:1px solid var(--line);
  box-shadow:0 24px 80px rgba(0,0,0,.5),0 0 0 1px rgba(34,211,238,.08)}
/* wechat qr (footer) */
.qr{margin-top:14px}
.qr img{width:96px;height:96px;border-radius:10px;display:block;border:1px solid var(--line)}
.qr span{display:block;font-size:.78rem;color:var(--muted);margin-top:6px}
/* city medallions (about page) */
.city-grid{display:grid;grid-template-columns:repeat(6,1fr);gap:18px;position:relative;margin-top:10px}
.city-grid::before{content:'';position:absolute;top:54px;left:7%;right:7%;height:3px;
  background:linear-gradient(90deg,rgba(34,211,238,.05),rgba(34,211,238,.45),rgba(124,58,237,.45),rgba(34,211,238,.05))}
.city-card{text-align:center;position:relative}
.city-card img{width:108px;height:108px;border-radius:50%;object-fit:cover;display:block;margin:0 auto;
  border:3px solid rgba(34,211,238,.45);box-shadow:0 0 0 6px rgba(8,12,20,1),0 8px 24px rgba(0,0,0,.4);
  transition:transform .25s,border-color .25s}
.city-card:hover img{transform:scale(1.06);border-color:var(--cyan)}
.city-card .city-body{padding:16px 4px 0}
.city-card h3{margin:0 0 2px;font-size:1rem}
.city-card h3::before{content:'📍 ';font-size:.8em}
.city-card .city-role{display:block;color:var(--cyan);font-size:.8rem;margin-bottom:8px}
.city-card p{margin:0;color:var(--muted);font-size:.8rem;line-height:1.5}
@media(max-width:900px){.city-grid{grid-template-columns:repeat(3,1fr);row-gap:34px}.city-grid::before{display:none}}
@media(max-width:640px){.city-grid{grid-template-columns:repeat(2,1fr)}}
.logo-cell img[src*="lubrizol"],.logo-cell img[src*="vanke"]{max-height:30px;max-width:75%}
@media(max-width:960px){.logo-wall{grid-template-columns:repeat(3,1fr)}}
@media(max-width:640px){.logo-wall{grid-template-columns:repeat(2,1fr)}}

/* timeline */
.timeline{position:relative;margin-top:20px;padding-left:28px}
.timeline::before{content:"";position:absolute;left:7px;top:6px;bottom:6px;width:2px;
  background:linear-gradient(180deg,var(--cyan),var(--violet))}
.tl-item{position:relative;padding:0 0 34px 18px}
.tl-item::before{content:"";position:absolute;left:-27px;top:7px;width:14px;height:14px;
  border-radius:50%;background:var(--bg);border:3px solid var(--cyan)}
.tl-item .year{font-weight:800;color:var(--cyan);font-size:1.05rem}
.tl-item h4{margin:4px 0 6px;font-size:1.05rem}
.tl-item p{color:var(--muted);font-size:.92rem}

/* table */
table.spec{width:100%;border-collapse:collapse;margin-top:16px;font-size:.92rem}
table.spec th,table.spec td{border:1px solid var(--line);padding:12px 14px;text-align:left}
table.spec th{background:var(--panel-2);color:var(--cyan);font-weight:700}
table.spec td{color:var(--muted)}
/* comparison table — highlight Irista column */
table.compare{min-width:860px}
table.compare td:first-child{color:var(--txt);font-weight:600}
table.compare th:last-child{background:linear-gradient(160deg,rgba(34,211,238,.18),rgba(124,58,237,.18));color:#fff}
table.compare td:last-child{color:var(--txt);background:rgba(34,211,238,.05);font-weight:500}
/* self-learning loop stepper */
.flow-steps{display:grid;grid-template-columns:repeat(5,1fr);gap:16px;margin-top:14px;position:relative}
.flow-steps::before{content:"";position:absolute;top:33px;left:9%;right:9%;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--violet));opacity:.4;z-index:0}
.flow-step{position:relative;z-index:1;text-align:center;padding:0 8px}
.flow-step .fnum{width:50px;height:50px;border-radius:50%;background:var(--grad);color:#fff;
  font-weight:800;font-size:1.2rem;display:grid;place-items:center;margin:0 auto 14px;
  box-shadow:0 6px 20px rgba(59,130,246,.35),0 0 0 6px var(--bg)}
.flow-step h4{font-size:1rem;margin-bottom:8px;color:var(--txt)}
.flow-step h4 .en{display:block;font-size:.72rem;font-weight:600;color:var(--cyan);letter-spacing:.5px;margin-top:2px}
.flow-step p{font-size:.85rem;color:var(--muted);line-height:1.55}
@media(max-width:760px){.flow-steps{grid-template-columns:1fr 1fr;gap:24px}.flow-steps::before{display:none}}
@media(max-width:460px){.flow-steps{grid-template-columns:1fr}}

/* FAQ */
details.faq{border:1px solid var(--line);border-radius:12px;margin-bottom:12px;
  background:var(--panel);overflow:hidden}
details.faq summary{cursor:pointer;padding:18px 22px;font-weight:600;list-style:none;position:relative}
details.faq summary::after{content:"+";position:absolute;right:22px;color:var(--cyan);font-size:1.3rem}
details.faq[open] summary::after{content:"−"}
details.faq .ans{padding:0 22px 18px;color:var(--muted);font-size:.94rem}

/* CTA band */
.cta-band{text-align:center;padding:84px 24px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  background:radial-gradient(ellipse at center,rgba(59,130,246,.12),transparent 70%)}
.cta-band h2{font-size:clamp(1.6rem,3.5vw,2.4rem);font-weight:800}
.cta-band p{color:var(--muted);margin:14px auto 30px;max-width:560px}

/* footer */
footer{padding:56px 0 36px;border-top:1px solid var(--line);background:var(--bg-2)}
.foot-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.4fr;gap:36px}
footer h4{font-size:.92rem;color:var(--txt);margin-bottom:14px;letter-spacing:1px}
footer a,footer p{display:block;color:var(--muted);font-size:.88rem;margin-bottom:8px}
footer a:hover{color:var(--cyan)}
.foot-bottom{margin-top:40px;padding-top:22px;border-top:1px solid var(--line);
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;color:var(--muted);font-size:.82rem}

/* page hero (sub pages) */
.page-hero{padding:72px 0 40px}
.page-hero h1{font-size:clamp(1.9rem,4.5vw,2.8rem);font-weight:800}
.page-hero h1 .grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.page-hero p{color:var(--muted);margin-top:16px;max-width:740px;font-size:1.05rem}
.breadcrumb{font-size:.84rem;color:var(--muted);margin-bottom:18px}
.breadcrumb a{color:var(--muted)}
.breadcrumb a:hover{color:var(--cyan)}

/* scroll reveal */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.reveal.in{opacity:1;transform:none}

@media(max-width:960px){
  .grid-3,.grid-4{grid-template-columns:repeat(2,1fr)}
  .stats{grid-template-columns:repeat(2,1fr)}
  .case{grid-template-columns:1fr}
  .foot-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:640px){
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  nav.menu{display:none;position:absolute;top:64px;left:0;right:0;flex-direction:column;
    background:rgba(6,9,15,.97);padding:18px 24px;gap:16px;border-bottom:1px solid var(--line);align-items:flex-start}
  nav.menu.open{display:flex}
  .nav-toggle{display:block}
  .has-sub{width:100%}
  .has-sub .submenu{display:none;position:static;transform:none;min-width:0;border:none;
    box-shadow:none;background:transparent;padding:6px 0 2px 14px}
  .has-sub.open .submenu{display:flex}
  .has-sub.open>a .caret{transform:rotate(180deg)}
  .hero{padding:64px 0 56px}
}