:root{--bg:#0d1117;--pan:#151b23;--pan2:#1b222c;--ln:#2a3340;--tx:#e6edf3;--mu:#9aa5b3;--ok:#2ea043;--bad:#f85149;--warn:#d29922;--acc:#58a6ff;--fiq:#a371f7}
*{box-sizing:border-box}html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--tx);font:16px/1.6 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
a{color:var(--acc)}a:focus-visible,.btn:focus-visible,input:focus-visible,textarea:focus-visible,video:focus-visible{outline:2px solid var(--acc);outline-offset:2px}
code{font-family:ui-monospace,"SF Mono",Menlo,Consolas,monospace;font-size:.9em;background:var(--pan2);padding:1px 5px;border-radius:4px;overflow-wrap:anywhere}
.skip{position:absolute;left:-999px;top:8px;background:var(--acc);color:#0d1117;padding:8px 14px;border-radius:6px;z-index:9}.skip:focus{left:8px}
.top{position:sticky;top:0;z-index:5;display:flex;align-items:center;gap:20px;flex-wrap:wrap;padding:12px 24px;border-bottom:1px solid var(--ln);background:rgba(21,27,35,.95)}
.logo{font-weight:700;font-size:19px;color:var(--tx);text-decoration:none}.logo b{color:var(--acc)}
nav{display:flex;gap:16px;flex-wrap:wrap;margin-left:auto}nav a{color:var(--mu);text-decoration:none;font-size:14px}nav a:hover{color:var(--tx)}
main{max-width:1120px;margin:0 auto;padding:0 24px}
section{padding:56px 0;border-bottom:1px solid var(--ln);scroll-margin-top:60px}
h1{font-size:clamp(26px,4.2vw,44px);line-height:1.2;margin:18px 0 28px;max-width:900px}
h2{font-size:clamp(22px,3vw,30px);margin:0 0 20px;display:flex;align-items:center;gap:12px;flex-wrap:wrap}
h3{margin:0 0 8px;font-size:18px}
.hero{padding:80px 0 72px}
.pill{display:inline-flex;align-items:center;gap:7px;padding:5px 12px;border-radius:999px;border:1px solid var(--ln);background:var(--pan2);font-size:13px;color:var(--mu);font-weight:500}
.dot{width:8px;height:8px;border-radius:50%;background:var(--mu)}.dot.ok{background:var(--ok)}.dot.warn{background:var(--warn)}.dot.fiq{background:var(--fiq)}
.btn{display:inline-block;border:1px solid var(--ln);background:var(--pan2);color:var(--tx);padding:11px 20px;border-radius:8px;font:inherit;font-weight:600;cursor:pointer;text-decoration:none}
.btn.primary{background:var(--acc);border-color:var(--acc);color:#0d1117}.btn.primary:hover{background:#79b8ff}
.card{background:var(--pan);border:1px solid var(--ln);border-radius:12px;padding:20px 22px;min-width:0}
.card p{margin:0 0 10px}.card p:last-child{margin-bottom:0}
.warnc{border-top:3px solid var(--warn)}.okc{border-top:3px solid var(--ok)}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.steps{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.n{display:inline-grid;place-items:center;width:30px;height:30px;border-radius:50%;background:var(--pan2);border:1px solid var(--acc);color:var(--acc);font-weight:700;margin-bottom:10px}
.lede{color:var(--mu);max-width:820px;margin:0 0 22px}.lede strong{color:var(--tx)}
.mu{color:var(--mu)}.small{font-size:14px}
.rng{margin:12px 0 16px;display:grid;gap:8px}.rng div{display:flex;gap:14px;align-items:baseline;flex-wrap:wrap}
.rng dt{width:40px;font-weight:700;color:var(--mu);font-size:14px}.rng dd{margin:0}.rng strong{font-size:clamp(20px,2.6vw,26px);font-variant-numeric:tabular-nums}
.okc .rng div:first-child strong{color:#3fb950}
.ex{font-size:14px;color:var(--mu)}
sup a{text-decoration:none;padding:0 2px}
.fn{margin:26px 0 0;padding-left:20px;font-size:13.5px;color:var(--mu)}.fn li{margin-bottom:8px}
.video video{width:100%;height:auto;display:block;border-radius:8px;background:#000}.video p{margin-top:10px}
ul{margin:0;padding-left:20px}li{margin-bottom:4px}
.form{display:grid;gap:8px;max-width:620px}
input,textarea{width:100%;background:var(--bg);color:var(--tx);border:1px solid var(--ln);border-radius:8px;padding:10px 12px;font:inherit}
label{font-weight:600;font-size:14px;margin-top:6px}.form .btn{justify-self:start;margin-top:8px}
footer{max-width:1120px;margin:0 auto;padding:28px 24px}
@media (max-width:820px){.grid2,.steps{grid-template-columns:1fr}.hero{padding:48px 0}section{padding:40px 0}nav{margin-left:0;gap:12px}main,.top,footer{padding-left:16px;padding-right:16px}}
h3 .pill{vertical-align:middle;margin-left:6px;font-size:12px}
footer p{margin:0 0 6px}
/* v3: Break the fabric simulator */
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.simlabel{margin:0 0 14px;color:var(--warn)}
.simctl{display:flex;flex-wrap:wrap;gap:10px;margin:0 0 16px}
.btn:focus-visible{outline:2px solid var(--acc);outline-offset:2px}
.btn[aria-pressed="true"]{border-color:var(--ok);color:#3fb950}.btn[aria-pressed="false"]{border-color:var(--warn);color:var(--warn)}
.simgrid{display:grid;grid-template-columns:3fr 2fr;gap:20px;align-items:start}
#sim-svg{width:100%;height:auto;display:block}
#sim-svg .wire{stroke:#3a4656;stroke-width:3}
#sim-svg .hit{stroke:transparent;stroke-width:18}
#sim-svg .lnk{cursor:pointer;outline:none}
#sim-svg .lnk:hover .wire{stroke:var(--mu)}
#sim-svg .lnk:focus-visible .wire{stroke:var(--acc);stroke-width:6}
#sim-svg .lnk.cut .wire{stroke:var(--bad);stroke-dasharray:8 8;stroke-width:4}
#sim-svg .node rect{fill:var(--pan2);stroke:var(--ln);stroke-width:2}
#sim-svg .node text{fill:var(--tx);font:600 20px system-ui,sans-serif;text-anchor:middle}
#sim-svg .node text.sub{fill:var(--mu);font:15px ui-monospace,monospace}
#sim-svg .spine{cursor:pointer;outline:none}
#sim-svg .spine:hover rect{stroke:var(--mu)}
#sim-svg .spine:focus-visible rect{stroke:var(--acc);stroke-width:4}
#sim-svg .spine.gray rect{stroke:var(--warn);stroke-width:3;fill:#2b2414}
#sim-svg .flow{fill:var(--acc);opacity:.85}
#sim-svg .flow.bad{fill:var(--bad)}
#sim-svg .flow.moved{fill:#3fb950}
.simkey{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:8px}
.k{display:inline-block;width:10px;height:10px;border-radius:50%;background:var(--acc)}.k.mv{background:#3fb950}.k.bad{background:var(--bad)}
.simread dl{margin:0 0 10px;display:grid;gap:8px}
.simread dt{font-size:13px;color:var(--mu)}.simread dd{margin:0;font-variant-numeric:tabular-nums;overflow-wrap:anywhere}
.simread dd.big{font-size:clamp(26px,3.4vw,34px);font-weight:700}
#sim.done #sim-clock{color:var(--tx)}
.simlog{list-style:none;padding:0;margin:6px 0 0;font:13px/1.5 ui-monospace,"SF Mono",Menlo,Consolas,monospace;min-height:60px}
.simlog .t{color:var(--acc);display:inline-block;min-width:78px}
@media (max-width:820px){.simgrid{grid-template-columns:1fr}}

.hero .tagline{margin:.4rem 0 1rem;color:var(--mu,#8b949e);font-size:1.05rem}
.card .sub{margin-top:1rem;padding-top:.8rem;border-top:1px solid rgba(139,148,158,.3)}
.card .sub h4{margin:0 0 .3rem;font-size:1rem}

#nip-card{margin-top:20px}