:root{
  --paper:#ecebe5; --paper-2:#e3e1d9; --ink:#121211; --ink-2:#3b3a36; --mute:#74716a;
  --rule:rgba(18,18,17,.16); --rule-2:rgba(18,18,17,.32);
  --signal:#ff4f1a; --go:#23a55a; --caution:#f2b21b; --stop:#e0352b;
  --board:#141413; --board-2:#1d1d1b; --board-line:#2c2c29; --chalk:#f0eee6; --chalk-2:#9b988f;
  --display:"Archivo",system-ui,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,Menlo,monospace;
  --pad:32px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{background:var(--paper);color:var(--ink);font-family:var(--display);line-height:1.5;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit}
code,.mono{font-family:var(--mono);font-size:.92em}
::selection{background:var(--signal);color:var(--ink)}
.wrap{max-width:1320px;margin:0 auto;padding:0 var(--pad);position:relative}
@media(max-width:700px){:root{--pad:16px}}

/* paper texture: faint dot screen */
body::before{content:"";position:fixed;inset:0;z-index:-1;pointer-events:none;
  background-image:radial-gradient(rgba(18,18,17,.06) 1px,transparent 1.2px);background-size:6px 6px}

/* ───────── nav ───────── */
.top{position:sticky;top:0;z-index:30;background:rgba(236,235,229,.92);backdrop-filter:blur(6px);border-bottom:1px solid var(--ink)}
.top .wrap{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;height:56px}
.mark{font-family:var(--display);font-stretch:125%;font-weight:800;font-size:22px;letter-spacing:-.02em;text-decoration:none;line-height:1}
.mark b{color:var(--signal);font-weight:800}
.links{display:flex;align-items:center;gap:28px;list-style:none;font-family:var(--mono);font-size:12px;text-transform:uppercase;letter-spacing:.06em}
.links a{text-decoration:none;display:flex;gap:6px;align-items:center}
.links a span{color:var(--mute)}
.links a:hover{color:var(--signal)}
.lang{justify-self:end;display:flex;font-family:var(--mono);font-size:12px;border:1px solid var(--ink)}
.lang a{text-decoration:none;padding:4px 9px;line-height:1.2}
.lang a[aria-current]{background:var(--ink);color:var(--paper)}
.lang a:not([aria-current]):hover{background:var(--signal)}
@media(max-width:860px){.links{display:none}.top .wrap{grid-template-columns:1fr auto}}

/* ───────── spec strip ───────── */
.spec{border-bottom:1px solid var(--rule-2);font-family:var(--mono);font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-2)}
.spec .wrap{display:flex;flex-wrap:wrap}
.spec span{padding:9px 18px 9px 0;margin-right:18px;border-right:1px solid var(--rule)}
.spec span:last-child{border-right:0}
.spec em{font-style:normal;color:var(--mute)}
.lamp{display:inline-block;width:8px;height:8px;border-radius:50%;background:var(--signal);margin-right:6px;box-shadow:0 0 0 2px rgba(255,79,26,.2);animation:lamp 1.6s steps(2) infinite}
@keyframes lamp{50%{opacity:.25}}
@media(max-width:700px){.spec span:nth-child(n+3){display:none}}

/* ───────── hero ───────── */
.hero{padding-top:44px}
.h1{font-family:var(--display);font-weight:900;font-stretch:68%;text-transform:uppercase;line-height:.84;letter-spacing:-.012em;font-size:clamp(50px,11vw,172px)}
.h1 .l{display:block;overflow:hidden;padding-bottom:.07em;margin-bottom:-.05em}
.h1 .l>span{display:inline-block;transform:translateY(105%);animation:rise .9s cubic-bezier(.2,.8,.1,1) forwards}
.h1 .l:nth-child(2)>span{animation-delay:.12s}
.h1 .dot{color:var(--signal)}
@keyframes rise{to{transform:none}}
.hero-grid{display:grid;grid-template-columns:5fr 7fr;margin-top:40px;border-top:1px solid var(--ink)}
.hero-copy{padding:28px 36px 36px 0;border-right:1px solid var(--ink)}
.hero-copy p{font-size:clamp(18px,1.6vw,22px);line-height:1.42;color:var(--ink-2);max-width:30ch}
.hero-copy p b{color:var(--ink);font-weight:600}
.install{margin-top:30px;display:flex;border:1px solid var(--ink);font-family:var(--mono);max-width:420px}
.install code{flex:1;padding:13px 14px;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.install code::before{content:"$ ";color:var(--mute)}
.install button{font-family:var(--mono);font-size:12px;text-transform:uppercase;letter-spacing:.06em;background:var(--ink);color:var(--paper);border:0;padding:0 16px;cursor:pointer;min-width:92px}
.install button:hover{background:var(--signal);color:var(--ink)}
.go{display:inline-flex;align-items:center;gap:12px;margin-top:18px;font-family:var(--mono);font-size:13px;text-transform:uppercase;letter-spacing:.06em;text-decoration:none;border-bottom:2px solid var(--signal);padding-bottom:3px}
.go:hover{color:var(--signal)}
.hero-copy .hero-note{margin-top:34px;font-family:var(--mono);font-size:11.5px;color:var(--mute);line-height:1.6;max-width:44ch}
@media(max-width:980px){.hero-grid{grid-template-columns:1fr}.hero-copy{border-right:0;padding-right:0;border-bottom:1px solid var(--ink)}}

/* dark hardware module */
.module{background:var(--board);color:var(--chalk);position:relative}
.module::before,.module::after{content:"";position:absolute;width:7px;height:7px;border-radius:50%;background:#3a3a36;box-shadow:inset 0 0 0 1.5px #222;top:10px}
.module::before{left:10px}.module::after{right:10px}
.board-head{display:flex;justify-content:space-between;gap:12px;font-family:var(--mono);font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--chalk-2);padding:14px 26px;border-bottom:1px solid var(--board-line)}
.board-head b{color:var(--chalk);font-weight:500}
.board-foot{font-family:var(--mono);font-size:11px;color:var(--chalk-2);padding:12px 26px;border-top:1px solid var(--board-line);display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}
.tag{font-family:var(--mono);font-size:10.5px;text-transform:uppercase;letter-spacing:.08em;border:1px solid currentColor;padding:1px 6px;white-space:nowrap}
.tag.warn{color:var(--caution)}

/* switchboard */
.sw{padding:6px 10px 0}
.sw svg{display:block;width:100%;height:auto;touch-action:manipulation}
.sw text{font-family:var(--mono)}
.jack{cursor:pointer}
.jack .ring{fill:#0b0b0a;stroke:#4a4944;stroke-width:2;transition:stroke .2s}
.jack:hover .ring,.jack.sel .ring{stroke:var(--signal)}
.jack.sel .ring{stroke-width:3.5}
.jack:focus{outline:none}
.jack:focus-visible .ring{stroke:var(--caution);stroke-width:3.5}
.readout{display:grid;grid-template-columns:1fr 1fr;border-top:1px solid var(--board-line);font-family:var(--mono);font-size:12px}
.readout>div{padding:14px 26px 18px;min-width:0}
.readout>div+div{border-left:1px solid var(--board-line)}
.readout h5{font-weight:500;font-size:10.5px;text-transform:uppercase;letter-spacing:.08em;color:var(--chalk-2);margin-bottom:8px;display:flex;justify-content:space-between;gap:8px}
.readout pre{font-family:var(--mono);font-size:12px;line-height:1.65;white-space:pre;color:var(--chalk);overflow:hidden}
.readout .ok{color:var(--go)}
.readout .k{color:var(--chalk-2)}
.readout .hot{color:var(--signal)}
@media(max-width:620px){.readout{grid-template-columns:1fr}.readout>div+div{border-left:0;border-top:1px solid var(--board-line)}.board-head,.board-foot,.readout>div{padding-left:16px;padding-right:16px}}

/* ───────── event tape ───────── */
.tape{background:var(--signal);color:var(--ink);border-top:1px solid var(--ink);border-bottom:1px solid var(--ink);overflow:hidden;display:flex;font-family:var(--mono);font-size:12.5px;white-space:nowrap;margin-top:72px}
.tape .lbl{flex:none;background:var(--ink);color:var(--signal);padding:10px 16px;text-transform:uppercase;letter-spacing:.08em;font-size:11px;z-index:1}
.tape .run{display:flex;animation:tape 70s linear infinite}
.tape .run span{padding:10px 22px;border-right:1px solid rgba(18,18,17,.35)}
.tape .run span i{font-style:normal;opacity:.55;margin-right:8px}
@keyframes tape{to{transform:translateX(-50%)}}

/* ───────── sections ───────── */
section{padding-bottom:40px}
.sh{display:grid;grid-template-columns:120px 1fr auto;align-items:baseline;border-top:1px solid var(--ink);padding-top:14px;font-family:var(--mono);font-size:12px;text-transform:uppercase;letter-spacing:.08em;margin-top:120px}
.sh .n{color:var(--signal)}
.sh .ref{color:var(--mute);text-transform:none;letter-spacing:0}
@media(max-width:700px){.sh{grid-template-columns:60px 1fr;margin-top:90px}.sh .ref{display:none}}
.h2{font-family:var(--display);font-weight:800;font-stretch:75%;text-transform:uppercase;line-height:.92;font-size:clamp(40px,6vw,88px);margin-top:36px;max-width:17ch}
.h2.wide{max-width:24ch}
.h2 em{font-style:normal;color:var(--signal)}
.lede{font-size:clamp(17px,1.4vw,20px);color:var(--ink-2);max-width:58ch;margin-top:22px;line-height:1.5}
.cols{display:grid;grid-template-columns:6fr 5fr;gap:48px;align-items:end}
@media(max-width:980px){.cols{grid-template-columns:1fr;gap:0}}

/* problem table */
.sprawl{margin-top:56px;border-top:2px solid var(--ink);font-size:15px}
.sprawl .r{display:grid;grid-template-columns:200px 1fr 280px;border-bottom:1px solid var(--rule-2);align-items:center}
.sprawl .r>*{padding:15px 16px 15px 0}
.sprawl .rt{font-family:var(--display);font-stretch:75%;font-weight:700;text-transform:uppercase;font-size:22px;line-height:1}
.sprawl .paths{font-family:var(--mono);font-size:13px;color:var(--ink-2);display:flex;flex-wrap:wrap;gap:6px 18px}
.sprawl .fate{font-family:var(--mono);font-size:12px;color:var(--mute)}
.sprawl .fate s{color:var(--stop);text-decoration:none}
.sprawl .r.aq{background:var(--ink);color:var(--paper);border-bottom:0}
.sprawl .r.aq>*:first-child{padding-left:16px}
.sprawl .r.aq .rt b{color:var(--signal)}
.sprawl .r.aq .paths{color:var(--paper)}
.sprawl .r.aq .fate{color:var(--signal)}
.sprawl .head{font-family:var(--mono);font-size:10.5px;text-transform:uppercase;letter-spacing:.08em;color:var(--mute)}
.sprawl .head>*{padding-top:10px;padding-bottom:10px}
@media(max-width:820px){.sprawl .r{grid-template-columns:1fr;padding:12px 0}.sprawl .r>*{padding:4px 12px 4px 0}.sprawl .head{display:none}.sprawl .r.aq{padding:14px 0}.sprawl .r.aq>*{padding-left:16px}}

/* metro line */
.line-mod{margin-top:56px}
.line-mod .grid{display:grid;grid-template-columns:1fr 340px}
.metro{padding:18px 12px 6px;min-width:0}
.metro svg{width:100%;height:auto;display:block}
.metro text{font-family:var(--mono)}
.log{border-left:1px solid var(--board-line);font-family:var(--mono);font-size:11.5px;padding:14px 18px;height:330px;overflow:hidden;display:flex;flex-direction:column;justify-content:flex-end;color:var(--chalk-2)}
.log div{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;line-height:1.75;animation:in .3s ease;flex:none}
.log .seq{color:#5b5953;margin-right:8px}
.log .ev{color:var(--chalk)}
.log .bad{color:var(--stop)} .log .good{color:var(--go)} .log .warn{color:var(--caution)}
@keyframes in{from{opacity:0;transform:translateY(6px)}}
.locks{display:grid;grid-template-columns:repeat(4,1fr);border-top:1px solid var(--board-line)}
.lock{padding:14px 20px;font-family:var(--mono);font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--chalk-2);display:flex;gap:10px;align-items:center}
.lock+.lock{border-left:1px solid var(--board-line)}
.lock i{flex:none;width:12px;height:12px;border-radius:50%;background:#2e2d2a;box-shadow:inset 0 0 0 2px #1a1a18;transition:background .25s,box-shadow .25s}
.lock.g i{background:var(--go);box-shadow:0 0 10px rgba(35,165,90,.7)}
.lock.r i{background:var(--stop);box-shadow:0 0 10px rgba(224,53,43,.8)}
.lock.a i{background:var(--caution);box-shadow:0 0 10px rgba(242,178,27,.7)}
.lock b{color:var(--chalk);font-weight:500}
@media(max-width:980px){.line-mod .grid{grid-template-columns:1fr}.log{border-left:0;border-top:1px solid var(--board-line);height:190px}}
@media(max-width:700px){.locks{grid-template-columns:1fr 1fr}.lock:nth-child(3){border-left:0}.lock:nth-child(n+3){border-top:1px solid var(--board-line)}.lock{padding:12px 14px}}

.neq{font-family:var(--display);font-weight:900;font-stretch:62%;text-transform:uppercase;font-size:clamp(44px,8.4vw,126px);line-height:.9;margin-top:110px;display:flex;flex-wrap:wrap;gap:0 .22em;align-items:baseline}
.neq span{color:var(--signal);font-weight:300}
.neq-note{font-family:var(--mono);font-size:12px;color:var(--mute);margin-top:16px;max-width:76ch}

/* principles as a spec list */
.spec-list{margin-top:56px;border-top:2px solid var(--ink)}
.pr{display:grid;grid-template-columns:120px 1fr 1.3fr 250px;gap:0 28px;padding:28px 0;border-bottom:1px solid var(--rule-2);align-items:start}
.pr .num{font-family:var(--display);font-weight:900;font-stretch:62%;font-size:64px;line-height:.8;color:transparent;-webkit-text-stroke:1.5px var(--ink);transition:color .2s}
.pr:hover .num{color:var(--signal);-webkit-text-stroke-color:var(--signal)}
.pr h3{font-family:var(--display);font-weight:800;font-stretch:80%;text-transform:uppercase;font-size:26px;line-height:1}
.pr p{color:var(--ink-2);font-size:15.5px}
.pr .where{font-family:var(--mono);font-size:11.5px;line-height:1.55}
.pr .where dt{color:var(--mute);text-transform:uppercase;letter-spacing:.06em;font-size:10px}
.pr .where dd{margin-bottom:8px}
@media(max-width:1000px){.pr{grid-template-columns:72px 1fr}.pr p,.pr .where{grid-column:2;margin-top:10px}.pr .num{font-size:48px}}

/* signal lamps */
.signals{margin-top:56px}
.sig-row{display:grid;grid-template-columns:1.3fr repeat(4,1fr);border-bottom:1px solid var(--board-line);font-family:var(--mono);font-size:12.5px;align-items:center}
.sig-row:last-child{border-bottom:0}
.sig-row>div{padding:13px 20px}
.sig-row.h{font-size:10.5px;text-transform:uppercase;letter-spacing:.08em;color:var(--chalk-2)}
.sig-row .cap{color:var(--chalk)}
.sig{display:flex;align-items:center;gap:10px;color:#56544e;transition:color .3s}
.sig i{flex:none;width:14px;height:14px;border-radius:50%;background:#2a2927;box-shadow:inset 0 0 0 2px #1a1a18;transition:all .3s}
.sig.on{color:var(--chalk)}
.sig.on.native i{background:var(--go);box-shadow:0 0 12px rgba(35,165,90,.8)}
.sig.on.emulated i{background:var(--chalk);box-shadow:0 0 12px rgba(240,238,230,.6)}
.sig.on.degraded i{background:var(--caution);box-shadow:0 0 12px rgba(242,178,27,.8)}
.sig.on.rejected i{background:var(--stop);box-shadow:0 0 12px rgba(224,53,43,.8)}
@media(max-width:760px){.sig-row{grid-template-columns:1fr repeat(4,30px)}.sig-row>div{padding:11px 6px}.sig-row>div:first-child{padding-left:14px}.sig span{display:none}.sig-row.h>div:not(:first-child){font-size:0}.sig-row.h>div:not(:first-child)::after{content:attr(data-s);font-size:10px}}

/* split-flap board */
.status-grid{display:grid;grid-template-columns:7fr 5fr;gap:24px;margin-top:56px;align-items:start}
@media(max-width:1060px){.status-grid{grid-template-columns:1fr}}
.flapboard{padding-bottom:10px}
.fb-row{display:grid;grid-template-columns:auto 1fr auto;gap:18px;align-items:center;padding:9px 22px;border-bottom:1px solid #222220}
.fb-row:last-child{border-bottom:0}
.fb-row.h{font-family:var(--mono);font-size:10.5px;letter-spacing:.08em;color:var(--chalk-2);text-transform:uppercase;padding-top:14px;padding-bottom:10px}
.flap{display:inline-flex;gap:2px}
.flap i{font-style:normal;display:inline-grid;place-items:center;width:.8em;height:1.3em;background:var(--board-2);border-radius:2px;font-family:var(--mono);font-weight:500;font-size:15px;color:var(--chalk);position:relative;overflow:hidden}
.flap i::after{content:"";position:absolute;left:0;right:0;top:50%;height:1px;background:#0a0a09}
.flap.s-ok i{color:var(--go)} .flap.s-next i{color:var(--signal)} .flap.s-plan i{color:#8d8a82}
.fb-dest{font-family:var(--mono);font-size:13px;color:var(--chalk);overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
@media(max-width:620px){.fb-row{grid-template-columns:auto 1fr;gap:6px 12px;padding:10px 14px}.fb-row .flap.st{grid-column:1/-1}.flap i{font-size:12.5px}.fb-row.h>:last-child{display:none}}

.report{border:1px solid var(--ink);background:var(--paper);padding:26px 26px 22px;position:relative}
.report h4{font-family:var(--mono);font-weight:500;font-size:11px;text-transform:uppercase;letter-spacing:.08em;color:var(--mute);border-bottom:1px solid var(--rule-2);padding-bottom:10px;display:flex;justify-content:space-between;gap:10px}
.stamp{position:absolute;right:18px;top:-18px;transform:rotate(-6deg);background:var(--paper);font-family:var(--display);font-weight:900;font-stretch:70%;text-transform:uppercase;font-size:24px;color:var(--stop);border:3px solid var(--stop);padding:5px 12px 3px;line-height:1;opacity:.85;mix-blend-mode:multiply;pointer-events:none}
.stamp.wip{color:#b07d00;border-color:#b07d00}
.report .lead-note{font-family:var(--display);font-weight:700;font-stretch:85%;font-size:24px;line-height:1.2;margin-top:22px;max-width:30ch}
.report .foot{font-size:14px;color:var(--ink-2);margin-top:14px}
.ledger{display:grid;grid-template-columns:1fr 1fr;margin-top:24px;border:1px solid var(--ink)}
.ledger>div{padding:20px 22px}
.ledger>div+div{border-left:1px solid var(--ink);background:var(--paper-2)}
.ledger h4{font-family:var(--mono);font-weight:500;font-size:11px;text-transform:uppercase;letter-spacing:.08em;margin-bottom:12px}
.ledger ul{list-style:none;font-size:14.5px;display:grid;gap:9px}
.ledger li{padding-left:20px;position:relative}
.ledger li::before{position:absolute;left:0;font-family:var(--mono);font-weight:600}
.ledger .yes li::before{content:"✓";color:var(--go)}
.ledger .no li::before{content:"→";color:var(--signal)}
@media(max-width:620px){.ledger{grid-template-columns:1fr}.ledger>div+div{border-left:0;border-top:1px solid var(--ink)}}

/* questions */
.qs{margin-top:56px;border-top:2px solid var(--ink);counter-reset:q}
.q{display:grid;grid-template-columns:120px 1fr;padding:24px 0;border-bottom:1px solid var(--rule-2);align-items:baseline}
.q::before{counter-increment:q;content:"Q" counter(q);font-family:var(--mono);font-size:13px;color:var(--signal)}
.q p{font-family:var(--display);font-weight:700;font-stretch:85%;font-size:clamp(22px,2.6vw,36px);line-height:1.1;letter-spacing:-.01em;max-width:34ch}
@media(max-width:700px){.q{grid-template-columns:44px 1fr}}
.reply{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-top:56px;background:var(--signal);color:var(--ink);text-decoration:none;padding:30px 34px;border:1px solid var(--ink);transition:background .2s,color .2s}
.reply:hover{background:var(--ink);color:var(--signal)}
.reply strong{font-family:var(--display);font-weight:900;font-stretch:68%;text-transform:uppercase;font-size:clamp(36px,6vw,84px);line-height:.9}
.reply span{font-family:var(--mono);font-size:14px;text-align:right}
@media(max-width:700px){.reply{flex-direction:column;align-items:flex-start;padding:22px}.reply span{text-align:left}}

/* colophon */
footer{border-top:1px solid var(--ink);margin-top:120px;padding:26px 0 40px;font-family:var(--mono);font-size:11.5px;color:var(--ink-2)}
footer .wrap{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
footer dt{color:var(--mute);text-transform:uppercase;letter-spacing:.08em;font-size:10px;margin-bottom:4px}
footer a{text-decoration:none;border-bottom:1px solid var(--rule-2)}
footer a:hover{color:var(--signal);border-color:var(--signal)}
@media(max-width:760px){footer .wrap{grid-template-columns:1fr 1fr}}

/* reveal */
.rv{opacity:0;transform:translateY(18px);transition:opacity .7s ease,transform .7s cubic-bezier(.2,.8,.2,1)}
.rv.in{opacity:1;transform:none}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation:none!important;transition:none!important}
  .rv{opacity:1;transform:none}
  .h1 .l>span{transform:none}
}