@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght,SOFT,WONK@0,9..144,300..900,0..100,0..1;1,9..144,300..900,0..100,0..1&family=Instrument+Sans:ital,wght@0,400..700;1,400..700&family=JetBrains+Mono:wght@400;600&display=swap');
:root{
  --paper:#f4efe4; --paper-2:#ebe4d3; --ink:#1d1a16; --ink-2:#4a443b; --ink-3:#8b8373;
  --rule:#d9d0bc; --speed:#e8590c; --speed-2:#ffb27a; --calm:#127e86; --calm-2:#9fd7d6; --gold:#b8891a;
  --display:'Fraunces',Georgia,serif; --body:'Instrument Sans',system-ui,sans-serif; --mono:'JetBrains Mono',monospace;
  --stage-w:560px; --stage-h:420px;
}
*{box-sizing:border-box}
html,body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:18px;line-height:1.55;min-height:100vh}
body{background-image:radial-gradient(ellipse at 20% 0%, #fbf7ee 0%, transparent 55%), radial-gradient(ellipse at 100% 100%, #e6dcc6 0%, transparent 50%);}
body::after{content:"";position:fixed;inset:0;pointer-events:none;opacity:.35;mix-blend-mode:multiply;background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .08 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");}
h1,h2,h3{font-family:var(--display);font-weight:500;line-height:1.08;letter-spacing:-.01em;margin:0 0 .5em;font-variation-settings:"opsz" 144,"SOFT" 30,"WONK" 1}
h1{font-size:clamp(2.4rem,5.5vw,4.6rem)} h2{font-size:clamp(1.7rem,3.2vw,2.6rem)} h3{font-size:1.25rem}
p{margin:0 0 1em;max-width:34em} p.lede{font-size:1.25rem;color:var(--ink-2)}
em{font-style:italic} strong{font-weight:600}
a{color:var(--calm);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
.speed{color:var(--speed)} .calm{color:var(--calm)} .mono{font-family:var(--mono);font-size:.9em}
.muted{color:var(--ink-3)} small,.small{font-size:.85rem;color:var(--ink-3)}

/* deck */
main.deck{min-height:100vh;padding:3rem 5vw 5.5rem;display:grid;place-items:center;position:relative;z-index:1}
section.slide{display:none;width:min(1180px,100%);animation:rise .5s ease both}
section.slide.active{display:block}
@keyframes rise{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.two{display:grid;grid-template-columns:1.05fr 1fr;gap:4rem;align-items:center}
.two.rev{grid-template-columns:1fr 1.05fr}
.center{text-align:center;display:grid;place-items:center} .center p{margin-inline:auto}
.narrow{max-width:38em;margin-inline:auto}
@media (max-width:900px){.two,.two.rev{grid-template-columns:1fr;gap:1.5rem}}

/* stage = fixed-size playable */
.stage{width:var(--stage-w);height:var(--stage-h);max-width:100%;background:#fbf8f1;border:1px solid var(--rule);border-radius:14px;box-shadow:0 1px 0 #fff inset,0 18px 40px -28px rgba(40,30,10,.45);position:relative;overflow:hidden}
.stage canvas{display:block;width:100%;height:100%}
.stage .hint{position:absolute;left:12px;bottom:10px;font-size:.78rem;color:var(--ink-3);pointer-events:none}
.stage .hud{position:absolute;right:12px;top:10px;font:600 .78rem var(--mono);color:var(--ink-2);text-align:right;line-height:1.5}
.controls{display:flex;flex-wrap:wrap;gap:.8rem 1.4rem;margin-top:1rem;align-items:center;font-size:.9rem}
.controls label{display:flex;align-items:center;gap:.5rem;color:var(--ink-2)}
input[type=range]{accent-color:var(--speed);width:180px}
input[type=range].calm{accent-color:var(--calm)}
.readout{font:600 .85rem var(--mono);padding:.15rem .5rem;border-radius:6px;background:var(--paper-2);color:var(--ink)}
button.btn,a.btn{font:600 .95rem var(--body);background:var(--ink);color:var(--paper);border:0;border-radius:999px;padding:.7rem 1.3rem;cursor:pointer;text-decoration:none;display:inline-block;transition:transform .15s,background .15s}
button.btn:hover,a.btn:hover{transform:translateY(-1px);background:#000}
button.btn.ghost,a.btn.ghost{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--ink)}
button.btn.speed{background:var(--speed)} button.btn.calm{background:var(--calm)}
.bets{display:flex;gap:.8rem;flex-wrap:wrap;margin:1.2rem 0}
.reveal{display:none} .unlocked .reveal, .reveal.show{display:block;animation:rise .5s ease both}
.nudge{animation:nudge .5s}
@keyframes nudge{25%{transform:translateX(-6px)}75%{transform:translateX(6px)}}

/* doors */
.door{display:inline-flex;align-items:center;gap:.5rem;font-size:.95rem;color:var(--ink);text-decoration:none;border:1.5px dashed var(--ink-3);border-radius:10px;padding:.55rem .9rem;margin:.3rem .4rem .3rem 0;background:rgba(255,255,255,.35);transition:all .15s}
.door:hover{border-style:solid;border-color:var(--ink);transform:translateY(-1px)}
.door::before{content:"↳";color:var(--speed);font-weight:700}
.door.next::before{content:"→"}
.door.back::before{content:"↩"}
.doors{margin-top:1.4rem}
.term{border-bottom:2px solid var(--speed-2);cursor:pointer;color:inherit;text-decoration:none;transition:background .15s;padding:0 .1em}
.term:hover{background:var(--speed-2)}
.tip{position:absolute;z-index:20;background:var(--ink);color:var(--paper);font-size:.9rem;padding:.7rem .9rem;border-radius:10px;max-width:22em;line-height:1.4;box-shadow:0 12px 30px -10px rgba(0,0,0,.5)}

/* quote block */
.quote{font-family:var(--display);font-size:clamp(1.2rem,2vw,1.6rem);line-height:1.35;font-weight:400;border-left:3px solid var(--speed);padding:.4rem 0 .4rem 1.4rem;margin:1.5rem 0;max-width:30em;font-variation-settings:"opsz" 60,"SOFT" 50}
.quote cite{display:block;font:italic .85rem var(--body);color:var(--ink-3);margin-top:.6rem}

/* equation chips */
.eq{font-family:var(--display);font-size:clamp(1.3rem,2.4vw,2.1rem);display:flex;flex-wrap:wrap;gap:.35em;align-items:baseline;justify-content:center;margin:1.5rem 0;font-variation-settings:"opsz" 144}
.eq .chip{padding:.1em .3em;border-radius:.3em;border:1.5px solid transparent;transition:all .15s}
.eq.live .chip{cursor:pointer}
.eq.live .chip:hover,.eq .chip.on{border-color:var(--ink);background:#fff}
a.eq{color:inherit;text-decoration:none}
.eq .chip.on{background:var(--speed-2)}

table.t{border-collapse:collapse;font-size:.95rem;margin:1rem 0}
table.t th,table.t td{text-align:left;padding:.5rem .9rem;border-bottom:1px solid var(--rule)}
table.t th{font-weight:600;color:var(--ink-3);font-size:.8rem;text-transform:uppercase;letter-spacing:.06em}
table.t td.n{font-family:var(--mono);text-align:right}

/* bar */
nav.bar{position:fixed;left:0;right:0;bottom:0;height:56px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;padding:0 1.2rem;background:rgba(244,239,228,.85);backdrop-filter:blur(10px);border-top:1px solid var(--rule);font-size:.85rem;z-index:10}
nav.bar .bar-map{justify-self:start;display:flex;gap:.5rem;align-items:center;color:var(--ink-2);text-decoration:none;font-weight:600;letter-spacing:.02em}
nav.bar .bar-map svg.ico{width:26px;height:26px;overflow:visible}
nav.bar .bar-map svg.ico .trk{fill:none;stroke:var(--ink-3);stroke-opacity:.45;stroke-width:3;stroke-linecap:round}
nav.bar .bar-map svg.ico .prg{fill:none;stroke:var(--ink);stroke-width:3;stroke-linecap:round;transition:stroke-dashoffset .6s ease}
nav.bar .bar-map svg.ico .eye{fill:var(--speed)}
nav.bar .bar-left{justify-self:start;display:flex;align-items:center;gap:1rem;min-width:0}
nav.bar .bar-title{font:italic .8rem var(--display);color:var(--ink-3);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
nav.bar .gate-hint{position:absolute;left:50%;transform:translateX(-50%);top:-2.2rem;background:var(--ink);color:var(--paper);font-size:.8rem;padding:.3rem .7rem;border-radius:6px;opacity:0;transition:opacity .2s;pointer-events:none}
nav.bar .gate-hint.show{opacity:1}
nav.bar .dots{display:flex;gap:9px;justify-self:center}
nav.bar .dot{width:12px;height:12px;border-radius:50%;border:2px solid var(--ink);background:transparent;cursor:pointer;padding:0;transition:transform .15s}
nav.bar .dot.seen{background:var(--ink-3);border-color:var(--ink-3)} nav.bar .dot.on{background:var(--ink);border-color:var(--ink);transform:scale(1.25)}
nav.bar .bar-arrows{justify-self:end;display:flex;gap:.4rem}
nav.bar .bar-arrows button{font:600 1rem var(--body);width:38px;height:38px;border-radius:50%;border:1.5px solid var(--ink);background:transparent;cursor:pointer;color:var(--ink)}
nav.bar .bar-arrows button:disabled{opacity:.25;cursor:default}
nav.bar .bar-arrows button:not(:disabled):hover{background:var(--ink);color:var(--paper)}

/* map page */
.map-wrap{min-height:100vh;display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:2rem;padding:3vh 6vw}
.map-head h1{font-size:clamp(2rem,4vw,3.4rem)}
.map-svg{width:100%;max-height:88vh}
.map-list{list-style:none;padding:0;margin:0;columns:1}
.map-list li{margin:.35rem 0}
.map-list a{color:var(--ink);text-decoration:none;display:flex;gap:.6rem;align-items:baseline}
.map-list a:hover .ttl{text-decoration:underline}
.map-list .side{padding-left:1.8rem;font-size:.92rem;color:var(--ink-2)}
.map-list .st{width:10px;height:10px;border-radius:50%;border:1.5px solid var(--ink);flex:none;transform:translateY(-1px)}
.map-list .st.seen{background:var(--ink-3);border-color:var(--ink-3)} .map-list .st.done{background:var(--ink)} .map-list .st.here{box-shadow:0 0 0 2.5px var(--paper),0 0 0 4.5px var(--speed)}
.map-list .num{font:600 .75rem var(--mono);color:var(--ink-3);width:2ch}
@media (max-width:900px){.map-wrap{grid-template-columns:1fr}}
.cards{display:grid;grid-template-columns:repeat(4,1fr);gap:.8rem;margin:1.4rem 0}
.card{font-family:var(--body);text-align:left;background:#fbf8f1;border:1.5px solid var(--rule);border-radius:12px;padding:.9rem;cursor:pointer;display:grid;gap:.25rem;transition:all .15s}
.card b{font:600 1.6rem var(--display);line-height:1} .card span{font-size:.95rem} .card small{color:var(--ink-3);font-size:.75rem}
.card:hover{border-color:var(--ink);transform:translateY(-2px)} .card.on{border-color:var(--speed);background:#fff3ea}
.card[data-k=C].on b,.card[data-k=D].on b{color:var(--speed)}
@media (max-width:800px){.cards{grid-template-columns:1fr 1fr}}
.timeline{display:grid;grid-template-columns:repeat(6,1fr);gap:.5rem;margin:1.5rem 0;position:relative}
.timeline::before{content:"";position:absolute;left:0;right:0;top:9px;height:2px;background:var(--rule)}
.tl-pt{background:none;border:0;font-family:var(--body);text-align:left;cursor:pointer;padding:0;display:grid;gap:.4rem;position:relative}
.tl-pt::before{content:"";width:16px;height:16px;border-radius:50%;background:var(--paper);border:2px solid var(--ink);display:block;position:relative;z-index:1;transition:all .15s}
.tl-pt:hover::before{transform:scale(1.2)} .tl-pt.on::before{background:var(--speed);border-color:var(--speed)}
.tl-pt .d{font:600 .75rem var(--mono);color:var(--ink-3)} .tl-pt .n{font-size:.9rem;font-weight:600}
.lean{padding:1.4rem;display:grid;gap:.8rem;font-size:.95rem;height:100%;align-content:start}
.lean .step{background:#fff;border:1px solid var(--rule);border-radius:10px;padding:.7rem .9rem;font-family:var(--mono);font-size:.82rem}
.lean .ok{color:var(--calm);font-weight:700} .lean .no{color:var(--speed);font-weight:700}
.lean .verdict{font:600 1rem var(--body);color:var(--calm);padding:.4rem 0} .lean .verdict.bad{color:var(--speed)}

/* motif: the spiral you are walking. Inked as deep as you are into the whole thing. */
svg.bg-spiral{position:fixed;right:-310px;bottom:-270px;width:900px;height:900px;z-index:0;pointer-events:none;overflow:visible}
svg.bg-spiral .trk{fill:none;stroke:var(--ink);stroke-opacity:.07;stroke-width:3;stroke-linecap:round}
svg.bg-spiral .prg{fill:none;stroke:var(--ink);stroke-opacity:.17;stroke-width:3;stroke-linecap:round;transition:stroke-dashoffset .8s cubic-bezier(.2,.7,.2,1)}
svg.bg-spiral .eye{fill:var(--speed);opacity:.45;r:6px}
svg.bg-spiral .eye.pulse{animation:pulse 1.6s ease-out infinite}
@keyframes pulse{0%,100%{transform:scale(1);opacity:.45}50%{transform:scale(2);opacity:.9}}
@media (max-width:900px){svg.bg-spiral{display:none}}

/* hook: an ink underline that coils into the vortex */
.coil{position:relative;padding-right:.55em;background:linear-gradient(currentColor,currentColor) no-repeat 0 100%/calc(100% - .55em) 1.5px}
.coil::after{content:"";position:absolute;right:-.15em;bottom:-.45em;width:.9em;height:.9em;background:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M2.0,12.0 2.3,10.4 2.8,8.8 3.6,7.4 4.6,6.1 5.8,5.1 7.1,4.3 8.5,3.7 10.0,3.4 11.5,3.3 12.9,3.5 14.3,3.9 15.5,4.5 16.7,5.3 17.6,6.3 18.4,7.4 18.9,8.6 19.3,9.8 19.4,11.1 19.3,12.3 19.0,13.5 18.5,14.6 17.9,15.6 17.1,16.4 16.2,17.1 15.2,17.6 14.2,17.9 13.2,18.1 12.1,18.0 11.1,17.8 10.2,17.5 9.4,17.0 8.7,16.4 8.1,15.6 7.7,14.9 7.4,14.1 7.3,13.2 7.3,12.4 7.4,11.6 7.7,10.9 8.0,10.2 8.5,9.7 9.0,9.2 9.6,8.9 10.3,8.7 10.9,8.6 11.5,8.6 12.1,8.7 12.6,8.9 13.1,9.1 13.5,9.5 13.8,9.9 14.0,10.3 14.1,10.7 14.2,11.1 14.2,11.5 14.1,11.9 13.9,12.2 13.7,12.5 13.5,12.7 13.2,12.9' fill='none' stroke='%23e8590c' stroke-width='1.6' stroke-linecap='round'/></svg>") no-repeat center/contain}

/* abcd: the four "doors" hinge open */
.cards{perspective:1100px}
.card{transform-origin:left center}
.card:hover{transform:rotateY(-16deg) translateY(-2px)}