/* Case study pages: same tokens as the homepage, dark-first, one blue accent, Geist */
:root{
  --bg:#0a0b0e; --surface:#121419; --surface-2:#171a20; --line:#22262e; --ink:#eceef2; --muted:#8b919c; --accent:#5b8cff; --green:#3ccf7a; --red:#ff5c6c;
  --sans:"Geist",system-ui,-apple-system,"PingFang SC","Noto Sans SC",sans-serif; --mono:"Geist Mono",ui-monospace,monospace; --ease:cubic-bezier(.16,1,.3,1);
  color-scheme:dark;
}
@media (prefers-color-scheme:light){:root:not([data-theme="dark"]){--bg:#ffffff;--surface:#f6f7f9;--surface-2:#eef0f4;--line:#e3e6ec;--ink:#0c0e13;--muted:#5a6170;--accent:#2a5bd7;color-scheme:light}}
*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--bg);color:var(--ink);font:17px/1.65 var(--sans);-webkit-font-smoothing:antialiased;overflow-x:clip}
img{max-width:100%;display:block}
a{color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.in{max-width:1180px;margin:0 auto;padding-left:max(20px,env(safe-area-inset-left,0px));padding-right:max(20px,env(safe-area-inset-right,0px))}
h1,h2,h3{margin:0;font-weight:600;letter-spacing:-.03em;line-height:1.08;text-wrap:balance}
p{margin:0}
section{padding-block:clamp(72px,10vw,128px)}
.eyebrow{font:500 12px var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--accent)}
.h2{font-size:clamp(30px,4vw,52px);margin-top:14px}
.lead{color:var(--muted);font-size:clamp(17px,1.5vw,20px);max-width:62ch;margin-top:18px}

/* nav */
nav{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--bg) 82%,transparent);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
nav .in{display:flex;align-items:center;gap:16px;height:64px}
nav .back{display:inline-flex;align-items:center;gap:8px;text-decoration:none;color:var(--muted);font-size:14px;transition:color .3s}
nav .back:hover{color:var(--ink)}
nav .brand{margin-right:auto;font-weight:600;text-decoration:none}
nav .lang{font:500 13px var(--sans);border:1px solid var(--line);background:none;color:var(--ink);border-radius:999px;padding:6px 11px;cursor:pointer;min-width:38px}
nav .lang:hover{border-color:var(--ink)}
html[lang="zh-CN"] .hero h1{font-size:clamp(34px,4.6vw,64px);max-width:18ch}
html[lang="zh-CN"] h1,html[lang="zh-CN"] h2,html[lang="zh-CN"] h3{letter-spacing:0;line-height:1.25}
@media (max-width:560px){nav .next{display:none}}
nav .next{font-size:14px;text-decoration:none;border:1px solid var(--line);border-radius:999px;padding:7px 14px;transition:border-color .3s}
nav .next:hover{border-color:var(--ink)}
.bar{position:fixed;left:0;top:0;height:2px;background:var(--accent);transform-origin:left;transform:scaleX(0);z-index:30;width:100%}

/* hero */
.hero{padding-block:clamp(56px,8vw,96px) 40px;position:relative;overflow:hidden}
.hero::before{content:"";position:absolute;right:-20%;top:-40%;width:80%;aspect-ratio:1;background:radial-gradient(closest-side,color-mix(in srgb,var(--glow,var(--accent)) 18%,transparent),transparent);pointer-events:none}
.hero h1{font-size:clamp(40px,6vw,84px);letter-spacing:-.045em;margin-top:18px;max-width:15ch}
.hero .lead{margin-top:22px}
.facts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px;margin-top:44px;padding-top:24px;border-top:1px solid var(--line)}
.facts dt{font:500 11px var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.facts dd{margin:6px 0 0;font-weight:500;font-size:15px}
.cover{margin-top:48px;border-radius:22px;overflow:hidden;border:1px solid var(--line);background:#07080b}
.cover img{width:100%;aspect-ratio:16/9;object-fit:cover}
@media (max-width:760px){.facts{grid-template-columns:1fr 1fr}}

/* kpis */
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));border-block:1px solid var(--line)}
.kpis div{padding:30px 24px;border-left:1px solid var(--line)}
.kpis div:first-child{border-left:0}
.kpis b{display:block;font-size:clamp(34px,4vw,52px);font-weight:600;letter-spacing:-.04em;line-height:1;font-variant-numeric:tabular-nums}
.kpis span{display:block;color:var(--muted);font-size:14px;margin-top:10px}
@media (max-width:760px){.kpis div{border-left:0;border-top:1px solid var(--line)}.kpis div:first-child{border-top:0}}

/* split blocks */
.split{display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:clamp(32px,6vw,88px);align-items:start}
@media (max-width:860px){.split{grid-template-columns:1fr}}
.pains{display:grid;gap:14px;margin:0;padding:0;list-style:none}
.pains li{display:grid;grid-template-columns:44px minmax(0,1fr);gap:14px;padding:18px;border:1px solid var(--line);border-radius:16px;background:linear-gradient(160deg,var(--surface),var(--bg))}
.ico{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;background:color-mix(in srgb,var(--accent) 12%,transparent);color:var(--accent);border:1px solid color-mix(in srgb,var(--accent) 30%,transparent)}
.ico svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.pains b{display:block;font-weight:600}
.pains span{color:var(--muted);font-size:15px}

/* steps timeline */
.steps{list-style:none;margin:48px 0 0;padding:0;position:relative;display:grid;gap:28px}
.steps::before{content:"";position:absolute;left:21px;top:8px;bottom:8px;width:2px;background:var(--line)}
.steps .fill{position:absolute;left:21px;top:8px;width:2px;height:calc(100% - 16px);background:var(--accent);transform-origin:top;transform:scaleY(0)}
.steps li{display:grid;grid-template-columns:44px minmax(0,1fr);gap:20px;position:relative}
.steps .ico{background:var(--bg);position:relative;z-index:1}
.steps h3{font-size:21px;margin-bottom:6px}
.steps p{color:var(--muted);max-width:62ch}

/* live canvas */
.live{background:var(--surface);border-block:1px solid var(--line)}
.live-box{margin-top:40px;border:1px solid var(--line);border-radius:20px;background:radial-gradient(90% 120% at 50% 0%,color-mix(in srgb,var(--accent) 10%,transparent),transparent),var(--bg);overflow:hidden}
.live-box canvas{display:block;width:100%;height:clamp(300px,42vw,460px)}
@media (max-width:640px){.live-box canvas[data-k="pipeline"]{height:440px}}
.live-cap{display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;padding:14px 20px;border-top:1px solid var(--line);font:500 12px var(--mono);color:var(--muted)}

/* architecture */
.arch{margin-top:44px;border:1px solid var(--line);border-radius:20px;padding:clamp(16px,3vw,32px);background:var(--surface);overflow-x:auto}
.arch svg{display:block;width:100%;min-width:640px;height:auto}
.arch .node rect{fill:var(--bg);stroke:var(--line);stroke-width:1.2}
.arch .node.hi rect{stroke:var(--accent);fill:color-mix(in srgb,var(--accent) 10%,var(--bg))}
.arch .node text{fill:var(--ink);font:600 13px var(--sans)}
.arch .node .sub{fill:var(--muted);font:500 10.5px var(--mono)}
.arch .edge{fill:none;stroke:color-mix(in srgb,var(--accent) 55%,var(--line));stroke-width:1.6}
.arch .flow{fill:none;stroke:var(--accent);stroke-width:2;stroke-dasharray:6 14;animation:flow 1.6s linear infinite}
.arch .zone{fill:none;stroke:var(--line);stroke-dasharray:4 6}
.arch .zl{fill:var(--muted);font:500 10px var(--mono);letter-spacing:.1em}
@keyframes flow{to{stroke-dashoffset:-40}}
.mech{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:24px}
.mech div{border:1px solid var(--line);border-radius:16px;padding:22px;background:linear-gradient(160deg,var(--surface),var(--bg))}
.mech h3{font-size:17px;margin:14px 0 8px}
.mech p{color:var(--muted);font-size:15px}
.mech code{font:500 13px var(--mono);color:var(--accent)}

/* detail image + quote */
.figure{margin:0;border-radius:22px;overflow:hidden;border:1px solid var(--line);background:#07080b}
.figure img{width:100%;aspect-ratio:16/10;object-fit:cover}
.hard{border-left:2px solid var(--accent);padding-left:28px;margin-top:40px}
.hard p{font-size:clamp(20px,2.2vw,28px);line-height:1.4;letter-spacing:-.01em}
.hard p+p{font-size:17px;color:var(--muted);margin-top:16px;letter-spacing:0}

/* results */
.results{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:16px;margin-top:40px;list-style:none;padding:0}
.results li{display:flex;gap:14px;align-items:flex-start;padding:20px;border:1px solid var(--line);border-radius:16px}
.results .ico{width:36px;height:36px;flex:none;background:color-mix(in srgb,var(--green) 14%,transparent);color:var(--green);border-color:color-mix(in srgb,var(--green) 35%,transparent)}
.results .ico svg{width:18px;height:18px}

/* next + footer */
.nextcard{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);border:1px solid var(--line);border-radius:22px;overflow:hidden;text-decoration:none;background:var(--surface);transition:border-color .4s}
.nextcard:hover{border-color:var(--accent)}
.nextcard .t{padding:clamp(24px,4vw,48px);display:flex;flex-direction:column;justify-content:center;gap:10px}
.nextcard h2{font-size:clamp(28px,3.4vw,44px)}
.nextcard .go{color:var(--accent);font-weight:500}
.nextcard img{width:100%;height:100%;object-fit:cover;min-height:240px;transition:transform .8s var(--ease)}
.nextcard:hover img{transform:scale(1.04)}
@media (max-width:760px){.nextcard{grid-template-columns:1fr}}
footer{padding-block:32px;border-top:1px solid var(--line);color:var(--muted);font-size:14px}
footer .in{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px}
footer a{color:var(--ink)}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}

/* engineering deep dive */
.deep{background:var(--surface);border-block:1px solid var(--line)}
.deep .sub{font-size:clamp(20px,2vw,26px);margin:72px 0 0}
.deep .sub:first-of-type{margin-top:48px}
.deep .subl{color:var(--muted);max-width:62ch;margin-top:10px}
.stack{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px;margin-top:24px}
.stack div{border:1px solid var(--line);border-radius:14px;padding:16px;background:var(--bg)}
.stack dt{font:500 11px var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.stack dd{margin:10px 0 0;display:flex;flex-wrap:wrap;gap:6px}
.stack dd span{font:500 13px var(--mono);padding:4px 10px;border-radius:999px;border:1px solid color-mix(in srgb,var(--accent) 35%,var(--line));color:var(--ink)}
.seq{list-style:none;margin:28px 0 0;padding:0;display:grid;gap:0;counter-reset:q;border:1px solid var(--line);border-radius:16px;overflow:hidden;background:var(--bg)}
.seq li{counter-increment:q;display:grid;grid-template-columns:44px 150px minmax(0,1fr);gap:16px;align-items:start;padding:16px 20px;border-top:1px solid var(--line)}
.seq li:first-child{border-top:0}
.seq li::before{content:counter(q,decimal-leading-zero);font:500 12px var(--mono);color:var(--accent);padding-top:2px}
.seq b{font:600 13px var(--mono);color:var(--ink)}
.seq span{color:var(--muted);font-size:15px}
@media (max-width:700px){.seq li{grid-template-columns:32px minmax(0,1fr)}.seq li span{grid-column:2}}
.states{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:24px;font:500 13px var(--mono)}
.states i{font-style:normal;padding:6px 12px;border-radius:999px;border:1px solid var(--line);background:var(--bg)}
.states i.ok{border-color:color-mix(in srgb,var(--green) 50%,transparent);color:var(--green)}
.states i.bad{border-color:color-mix(in srgb,var(--red) 50%,transparent);color:var(--red)}
.states em{font-style:normal;color:var(--muted)}
.dec{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:16px;margin-top:24px}
.dec article{border:1px solid var(--line);border-radius:16px;padding:22px;background:var(--bg);display:grid;gap:10px;align-content:start}
.dec h4{margin:0;font-size:18px}
.dec dl{margin:0;display:grid;gap:8px}
.dec dt{font:500 11px var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--accent)}
.dec dd{margin:0;color:var(--muted);font-size:15px}
.code{margin-top:24px;border:1px solid var(--line);border-radius:16px;overflow:hidden;background:#07080b}
.code .bar2{display:flex;justify-content:space-between;gap:12px;padding:10px 16px;border-bottom:1px solid var(--line);font:500 12px var(--mono);color:#8b919c}
.code pre{margin:0;padding:18px 20px;overflow-x:auto;font:13px/1.65 var(--mono);color:#cfd6e4}
.code .c{color:#6b7385}.code .k{color:#8fb0ff}.code .s{color:#9fe0ad}
.nums2{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:12px;margin-top:24px}
.nums2 div{border:1px solid var(--line);border-radius:14px;padding:18px;background:var(--bg)}
.nums2 b{display:block;font-size:28px;font-weight:600;letter-spacing:-.03em}
.nums2 span{font-size:13px;color:var(--muted)}
.ops{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:12px;margin-top:24px;list-style:none;padding:0}
.ops li{border-left:2px solid var(--accent);padding:6px 0 6px 16px}
.ops b{display:block}
.ops span{color:var(--muted);font-size:15px}