:root{--bg:#fff;--bg-2:#f6f6f3;--ink:#101214;--ink-2:#4a4f57;--muted:#80868f;--line:#e6e7e9;--line-2:#f0f0ee;--accent:#2b47ff;--accent-2:#1d33c9;--accent-soft:#e9edff;--blob-a:#e4e7ff;--blob-c:#e0f3f5}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:"Instrument Sans",-apple-system,BlinkMacSystemFont,"Segoe UI",Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased;line-height:1.62;font-size:17.5px;letter-spacing:-.005em}
a{color:inherit;text-decoration:none}
b,strong{font-weight:600}
.wrap{max-width:1180px;margin:0 auto;padding:0 36px}
@media(max-width:600px){.wrap{padding:0 20px}}
header.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;justify-content:space-between;height:74px;gap:24px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;font-size:19px;letter-spacing:-.02em}
.brand svg{width:22px;height:22px;display:block}
nav.links{display:flex;align-items:center;gap:34px}
nav.links a.txt{font-size:14.5px;font-weight:500;color:var(--muted)}
nav.links a.txt:hover{color:var(--ink)}
@media(max-width:700px){nav.links a.txt{display:none}nav.links{gap:14px}}
@media(max-width:400px){.nav-in{gap:10px}.brand{font-size:17px}.brand svg{width:19px;height:19px}nav.links .btn{padding:10px 13px;font-size:11px;letter-spacing:.04em}}
body{overflow-x:clip}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;font-weight:600;font-size:13px;letter-spacing:.06em;text-transform:uppercase;padding:14px 22px;border-radius:999px;border:1px solid var(--ink);color:var(--ink);background:transparent;transition:background .16s,color .16s,transform .16s;white-space:nowrap}
.btn:hover{background:var(--ink);color:#fff;transform:translateY(-1px)}
.btn-solid{background:var(--ink);color:#fff}
.btn-solid:hover{background:#000}
nav.links .btn{padding:11px 18px;font-size:12px}
.lab{display:inline-flex;align-items:center;gap:8px;font-size:11px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--ink);background:var(--accent-soft);border-radius:999px;padding:6px 11px;line-height:1}
.lab i{font-style:normal;color:var(--accent);font-weight:700}
.art{max-width:720px;margin:0 auto;padding:64px 30px 40px}
@media(max-width:600px){.art{padding:44px 20px 32px}}
.art h1{font-size:clamp(2.1rem,4.6vw,3.3rem);line-height:1.05;font-weight:500;letter-spacing:-.035em;text-wrap:balance;margin-top:22px}
.art .dek{margin-top:18px;font-size:20px;line-height:1.5;color:var(--ink-2);text-wrap:pretty}
.byline{display:flex;gap:8px 20px;flex-wrap:wrap;margin-top:24px;padding:14px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:12.5px;letter-spacing:.02em;color:var(--muted)}
.byline b{color:var(--ink);font-weight:600}
.art h2{font-size:clamp(1.4rem,2.6vw,1.8rem);line-height:1.2;font-weight:500;letter-spacing:-.03em;margin:46px 0 12px}
.art h3{font-size:1.2rem;font-weight:600;letter-spacing:-.02em;margin:30px 0 6px}
.art p{margin:16px 0;color:var(--ink-2)}
.art p.first{font-size:19px;color:var(--ink);margin-top:32px}
.art ul,.art ol{margin:16px 0 16px 4px;padding-left:20px;color:var(--ink-2)}
.art li{margin:8px 0}
.art strong{color:var(--ink)}
.art code{font-family:ui-monospace,Menlo,monospace;font-size:.88em;background:var(--accent-soft);padding:2px 6px;border-radius:5px;color:var(--accent-2)}
.art blockquote{margin:28px 0;padding:6px 0 6px 22px;border-left:2px solid var(--accent);font-size:1.3rem;line-height:1.35;color:var(--ink);letter-spacing:-.02em;font-weight:500}
.ledger{margin:26px 0;border:1px solid var(--line);border-radius:12px;background:#fff;overflow:hidden}
.ledger div{display:grid;grid-template-columns:1fr auto;gap:20px;padding:13px 18px;border-top:1px solid var(--line-2);font-size:15px;color:var(--ink-2)}
.ledger div:first-child{border-top:none}
.ledger div b{font-size:14px;color:var(--ink);font-weight:600;white-space:nowrap;font-variant-numeric:tabular-nums}
.ledger div.total{background:var(--bg-2);color:var(--ink);font-weight:600}
.ledger div.total b{color:var(--accent)}
.aside{margin:28px 0;padding:18px 22px;border:1px solid var(--line);border-radius:12px;background:var(--bg-2);font-size:15.5px;color:var(--ink-2)}
.aside b{color:var(--ink)}
.rec{margin:26px 0;border:1px solid var(--line);border-radius:12px;background:#fff;padding:18px 22px;font-family:ui-monospace,Menlo,monospace;font-size:13px;line-height:1.85;color:var(--ink-2);white-space:pre-wrap;overflow-x:auto}
.rec i{font-style:normal;color:var(--muted)}
.rec mark{background:var(--accent-soft);color:var(--ink);padding:1px 5px;border-radius:4px}
.rec mark.no{background:#fdecea;color:#8a1c17}
.cta{margin:56px 0 0;padding:32px 30px;border-radius:18px;background:linear-gradient(135deg,var(--blob-a),#f3f4ff 45%,var(--blob-c));border:1px solid var(--line)}
.cta h2{margin:0;font-size:1.5rem}
.cta p{color:var(--ink-2);margin:10px 0 20px}
.cta .btns{display:flex;gap:12px;flex-wrap:wrap}
.more{max-width:720px;margin:0 auto;padding:0 30px 64px}
@media(max-width:600px){.more{padding:0 20px 48px}}
.more .k{font-size:11px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin-bottom:10px}
.more a{display:block;padding:14px 0;border-top:1px solid var(--line);font-size:1.1rem;font-weight:500;letter-spacing:-.02em}
.more a:hover{color:var(--accent)}
.more a span{display:block;font-size:14px;color:var(--muted);font-weight:400;margin-top:3px}
footer{padding:30px 0;color:var(--muted);font-size:13.5px;border-top:1px solid var(--line)}
.foot-in{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:14px}
.foot-in a{color:var(--ink-2);display:inline-block;padding:6px 0;font-weight:500}
.foot-in a:hover{color:var(--accent)}
.foot-in .links{display:flex;gap:22px;flex-wrap:wrap}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px}

/* walkthrough panel, shared with the homepage system */
  /* 04 under the hood: the walkthrough on a soft gradient panel */
.panel{margin-top:44px;border-radius:22px;padding:22px;background:linear-gradient(135deg,var(--blob-a),#f3f4ff 45%,var(--blob-c));position:relative}
@media(max-width:600px){.panel{padding:10px;border-radius:16px}}
.demo{border:1px solid rgba(16,18,20,.08);border-radius:14px;background:#fff;overflow:hidden;box-shadow:0 30px 60px -36px rgba(16,18,20,.35)}
.demo-head{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 20px;border-bottom:1px solid var(--line);background:var(--bg-2)}
.dlabel{font-size:11px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);display:flex;align-items:center;gap:9px}
.dlabel::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--accent);animation:pulse 2.4s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:.35;transform:scale(.82)}}
.dreplay{font-family:inherit;font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--ink);background:#fff;border:1px solid var(--line);border-radius:999px;padding:7px 14px;cursor:pointer;transition:border-color .2s,color .2s}
.dreplay:hover{border-color:var(--ink)}
.demo-grid{display:grid;grid-template-columns:1.05fr 1fr}
@media(max-width:900px){.demo-grid{grid-template-columns:1fr}}
.srcpanel{border-right:1px solid var(--line);background:#fcfcfb}
@media(max-width:900px){.srcpanel{border-right:none;border-bottom:1px solid var(--line)}}
.srcbar{display:flex;align-items:center;gap:9px;padding:12px 20px;border-bottom:1px solid var(--line-2);font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.srcbar .dot{width:7px;height:7px;border-radius:50%;background:var(--line);flex:none}
.srcbar em{font-style:normal;color:#c4c6c9;margin-left:auto;font-weight:500}
.srccode{margin:0;padding:22px 20px;font-family:ui-monospace,"SF Mono",Menlo,Consolas,monospace;font-size:12.5px;line-height:1.95;color:var(--ink-2);white-space:pre-wrap;overflow-x:auto}
.srccode mark{background:transparent;color:inherit;padding:2px 4px;border-radius:4px;transition:background .45s,color .45s,box-shadow .45s}
.srccode mark.on{background:var(--accent-soft);color:var(--ink);box-shadow:inset 0 -2px 0 var(--accent)}
.srccode mark.fail{background:#fdecea;box-shadow:inset 0 -2px 0 #c62828;color:#8a1c17}
.srcfoot{display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;margin:6px 20px 20px;padding-top:14px;border-top:1px solid var(--line-2);font-size:11px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);opacity:0;transition:opacity .5s}
.srcfoot.on{opacity:1}
.pipe{padding:22px 24px 24px}
.stages{list-style:none;margin:0 0 20px;padding:0 0 18px;border-bottom:1px solid var(--line-2)}
.stages li{display:flex;gap:12px;align-items:flex-start;font-size:14.5px;line-height:1.5;color:var(--muted);padding:6px 0;opacity:.4;transition:opacity .45s,color .45s}
.stages li.on{opacity:1;color:var(--ink)}
.stages .sn{font-size:11px;font-weight:700;letter-spacing:.06em;color:var(--accent);padding-top:3px;flex:none}
.checks{list-style:none;margin:0;padding:0}
.checks li{display:flex;gap:11px;align-items:flex-start;font-size:14px;line-height:1.5;color:var(--muted);padding:7px 0;opacity:0;transform:translateY(6px);transition:opacity .4s,transform .4s,color .4s}
.checks li.on{opacity:1;transform:none;color:var(--ink-2)}
.checks li i{width:16px;height:16px;border-radius:50%;border:1px solid var(--line);flex:none;margin-top:2px;position:relative;transition:border-color .3s,background .3s}
.checks li.pass i{border-color:var(--accent);background:var(--accent)}
.checks li.pass i::after{content:"";position:absolute;left:5px;top:2px;width:4px;height:8px;border:solid #fff;border-width:0 1.5px 1.5px 0;transform:rotate(42deg)}
.checks li.fail i{border-color:#c62828;background:#c62828}
.checks li.fail i::after{content:"";position:absolute;left:7.2px;top:3.5px;width:1.5px;height:9px;background:#fff}
.checks li.fail{color:#8a1c17;flex-wrap:wrap}
.checks li b{display:none;font-weight:400;font-size:13px;line-height:1.5;margin-top:5px;color:#8a1c17;flex-basis:100%;padding-left:27px}
.checks li.fail b{display:block}
.outs{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid var(--line)}
@media(max-width:700px){.outs{grid-template-columns:1fr}}
.factcard{padding:20px 22px;opacity:0;transform:translateY(8px);transition:opacity .5s,transform .5s;border-right:1px solid var(--line)}
.factcard:last-child{border-right:none}
@media(max-width:700px){.factcard{border-right:none;border-bottom:1px solid var(--line)}}
.factcard.on{opacity:1;transform:none}
.ftag{font-size:10.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--accent)}
.factcard.rej .ftag{color:#c62828}
.fval{font-size:19px;letter-spacing:-.02em;margin-top:8px;font-weight:500}
.factcard.rej .fval{color:var(--muted);text-decoration:line-through;text-decoration-color:rgba(198,40,40,.5)}
.fcite{font-size:12px;color:var(--muted);margin-top:8px;line-height:1.6}
.demonote{padding:20px 22px;border-top:1px solid var(--line);background:var(--bg-2);font-size:15px;line-height:1.6;color:var(--ink-2);margin:0}
.demonote a{color:var(--accent);font-weight:600}


.artwide{--w:min(1080px,calc(100vw - 60px));width:var(--w);margin:26px 0 40px calc(50% - var(--w) / 2)}
@media(max-width:600px){.artwide{--w:calc(100vw - 40px)}}
.artwide .panel{margin-top:0}