:root{
  --paper:#f5f1e8;
  --ink:#141416;
  --ink-2:#45454b;
  --ink-3:#86837b;
  --line:rgba(20,20,22,.1);
  --sans:Inter,system-ui,-apple-system,Segoe UI,sans-serif;
  --serif:'Instrument Serif',Georgia,serif;
  --mono:'JetBrains Mono',ui-monospace,Menlo,monospace;
  --gut:clamp(16px,4vw,64px);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);-webkit-font-smoothing:antialiased}
html,body{overflow-x:clip}
a{color:inherit}
.mono{font-family:var(--mono)}

#scene{position:fixed;inset:0;width:100vw;height:100vh;z-index:0;pointer-events:none;display:block}
.fallback{display:none;position:fixed;inset:0;z-index:0;pointer-events:none;
  background:
   linear-gradient(180deg,var(--paper) 0%,var(--paper) 28%,rgba(245,241,232,0) 52%),
   radial-gradient(90% 60% at 50% 70%,#6c7480 0%,#2a2c33 55%,#16171b 100%)}
body.no-gl #scene{display:none}
body.no-gl .fallback{display:block}

/* nav */
.nav{position:fixed;top:0;left:0;right:0;z-index:50;display:flex;align-items:center;gap:24px;padding:16px var(--gut);background:linear-gradient(rgba(245,241,232,.92) 40%,rgba(245,241,232,0))}
.brand{display:flex;align-items:center;gap:9px;text-decoration:none;font-weight:700;font-size:18px;letter-spacing:-.02em}
.chip-ico{color:var(--ink)}
.links{flex:1;display:flex;justify-content:center;gap:30px}
.links a{text-decoration:none;font-size:14px;font-weight:500;color:var(--ink-2)}
.links a:hover{color:var(--ink)}
.right{display:flex;gap:10px;align-items:center}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:40px;padding:0 18px;border-radius:9px;font:600 14px/1 var(--sans);text-decoration:none;cursor:pointer;border:1px solid transparent;transition:background .2s,border-color .2s,transform .2s;white-space:nowrap}
.btn.dark{background:var(--ink);color:#fbf9f4;box-shadow:0 1px 0 rgba(255,255,255,.08) inset,0 10px 24px -12px rgba(0,0,0,.55)}
.btn.dark:hover{background:#2a2a2e}
.btn.ghost{background:rgba(250,248,243,.78);color:var(--ink);border-color:rgba(20,20,22,.14);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}
.btn.ghost:hover{border-color:var(--ink);background:#fbf9f4}
.btn.lg{height:50px;padding:0 26px;font-size:15px}
.btn.sm{height:30px;padding:0 11px;font-size:12px}
.btn[aria-disabled=true],.btn:disabled{opacity:.4;pointer-events:none}

/* chapters */
main{position:relative;z-index:2}
.ch{position:relative;height:175vh}
.ch-end{height:100vh}
.stick{position:sticky;top:0;height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:84px var(--gut) 48px;text-align:center}
.txt{position:relative;display:flex;flex-direction:column;align-items:center;max-width:1200px;width:100%}
.ch-top .stick{justify-content:flex-start;padding-top:110px}
.ch-hero .stick{justify-content:center;padding-top:84px}
.copy{text-shadow:0 0 14px rgba(245,241,232,.95),0 0 4px rgba(245,241,232,.9);color:var(--ink)}
.ch-pot .stick{justify-content:center;padding-top:150px;padding-bottom:48px}
.ch-low .stick{justify-content:flex-end;padding-bottom:64px}

.kicker{font:500 12px/1 var(--mono);letter-spacing:.22em;text-transform:uppercase;color:var(--ink-2);margin:0 0 18px}
.hl{margin:0;font-weight:600;font-size:clamp(52px,8.2vw,150px);line-height:.9;letter-spacing:-.05em;
  background:linear-gradient(180deg,#121214 0%,#1d1d21 45%,#55555b 100%);-webkit-background-clip:text;background-clip:text;color:transparent;padding-bottom:.08em}
.hl span,.hl em{display:block}
.hl em{font-family:var(--serif);font-style:italic;font-weight:400;letter-spacing:-.025em;font-size:1.1em;line-height:.92;padding:0 .06em}
.ch-hero .hl{font-size:clamp(64px,11vw,200px)}
.copy{margin:22px 0 0;font-size:clamp(16px,1.3vw,19px);line-height:1.5;color:var(--ink-2);max-width:32em;font-weight:500}
.acts{display:flex;gap:12px;margin-top:30px;flex-wrap:wrap;justify-content:center}
.small{font-size:12px;color:var(--ink-2);margin:20px 0 0}
.small a{color:var(--ink)}

/* text that sits on the dark die gets the light fill */
.on-die .kicker{color:rgba(245,241,232,.78)}
.on-die .hl{background-image:linear-gradient(180deg,#fbf9f4 0%,#e9e6df 45%,#9c9a95 100%)}
.on-die .copy{color:rgba(245,241,232,.86)}
.on-die .small,.on-die .small a{color:rgba(245,241,232,.8)}
.on-die .foot a{color:rgba(245,241,232,.75)}
.on-die .foot a:hover{color:#fff}
.on-die .lbl{color:rgba(245,241,232,.6)}
.on-die .val,.on-die .sub{color:#f5f1e8}
.on-die .stat{border-color:rgba(245,241,232,.18)}

/* text motion, only once JS is running */
body.js .txt{transition:opacity .7s ease,transform .9s cubic-bezier(.2,.7,.1,1)}
body.js .ch:not(.on) .txt{opacity:0;transform:translateY(28px)}
@media (prefers-reduced-motion:reduce){body.js .ch:not(.on) .txt{opacity:1;transform:none}html{scroll-behavior:auto}}

/* token row */
.tok{display:flex;align-items:center;gap:10px;margin-top:16px;flex-wrap:wrap;justify-content:center}
.ca{display:flex;align-items:center;gap:12px;height:40px;padding:0 6px 0 14px;border-radius:9px;background:rgba(250,248,243,.86);border:1px solid rgba(20,20,22,.12);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}
.ca-t{font:600 13px/1 var(--sans);letter-spacing:-.01em}
.ca code{font:400 13px/1 var(--mono);color:var(--ink-2)}
.ca-copy{height:28px;padding:0 10px;border-radius:7px;border:1px solid rgba(20,20,22,.14);background:#fff;font:600 12px/1 var(--sans);color:var(--ink);cursor:pointer}
.ca-copy:hover{border-color:var(--ink)}

/* pot stats */
.stats{display:flex;gap:0;margin-top:30px;flex-wrap:wrap;justify-content:center}
.stat{display:flex;flex-direction:column;gap:6px;padding:0 28px;border-left:1px solid var(--line);align-items:center}
.stat:first-child{border-left:0}
.lbl{font:500 11px/1 var(--mono);letter-spacing:.2em;text-transform:uppercase;color:var(--ink-3);margin:0}
.val{font-size:clamp(26px,2.6vw,38px);font-weight:600;letter-spacing:-.03em;text-decoration:none}
.sub{font-size:13px;color:var(--ink-2);text-decoration:none}

.foot{display:flex;gap:22px;margin-top:34px;font-size:12px;letter-spacing:.08em;text-transform:uppercase;justify-content:center}
.foot a{color:var(--ink-2);text-decoration:none}
.foot a:hover{color:var(--ink)}

/* try it: the real board as an app window */
.ch-try .stick{justify-content:flex-start;padding-top:96px;gap:0}
.ch-try .hl{font-size:clamp(46px,5.8vw,100px)}
.win{position:relative;z-index:1;margin-top:22px;width:min(820px,100%);text-align:left;background:#fbfaf7;border-radius:12px;
  box-shadow:0 0 0 1px rgba(20,20,22,.09),0 1px 0 rgba(255,255,255,.9) inset,0 2px 4px rgba(20,20,22,.06),0 30px 60px -20px rgba(10,10,14,.35),0 80px 140px -40px rgba(10,10,14,.5);
  font-size:14px;overflow:hidden}
.win-bar{display:flex;align-items:center;gap:20px;height:46px;padding:0 16px;border-bottom:1px solid var(--line);background:#f6f4ef}
.win-brand{display:flex;align-items:center;gap:7px;font-weight:700;font-size:14px;letter-spacing:-.01em}
.win-brand .chip-ico{width:17px;height:17px}
.win-tabs{display:flex;gap:18px;font-size:13px;font-weight:500;color:var(--ink-3)}
.win-tabs a{text-decoration:none}
.win-tabs a:hover{color:var(--ink)}
.win-tabs .on{color:var(--ink);text-decoration:underline;text-underline-offset:16px;text-decoration-thickness:1.5px}
.win-meta{margin-left:auto;font-size:11px;color:var(--ink-3);letter-spacing:.06em}
.win-body{display:grid;grid-template-columns:170px 1fr}
.win-side{border-right:1px solid var(--line);padding:16px 10px;display:flex;flex-direction:column;gap:2px;background:#f8f6f2}
.win-side .lbl{padding:0 10px 10px}
.win-side .t{display:flex;align-items:center;justify-content:space-between;height:34px;padding:0 10px;border-radius:8px;text-decoration:none;color:var(--ink-3);font-size:13px}
.win-side .t b{font-weight:500}
.win-side .t i{font:normal 400 11px var(--mono)}
.win-side a.t:hover{color:var(--ink);background:rgba(20,20,22,.04)}
.win-side .t.on{background:#ece9e2;color:var(--ink)}
.win-side .t.on b{font-weight:600}
.win-main{padding:18px 22px 20px}
.b-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:14px}
.b-head .lbl{margin-bottom:6px}
.b-head strong{font-size:24px;letter-spacing:-.03em}
.b-hint{margin:0;font-size:12px;color:var(--ink-3)}
.b-gates{display:flex;flex-direction:column;gap:6px}
.gate{display:grid;grid-template-columns:30px 44px 1fr 1fr 28px;align-items:center;gap:8px}
.gate .gid{font:500 12px var(--mono)}
.gate .fn{font:400 11px var(--mono);color:var(--ink-3)}
select{appearance:none;-webkit-appearance:none;font:500 12px var(--mono);color:var(--ink);background:#fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%23141416' stroke-width='1.3'/%3E%3C/svg%3E") no-repeat right 8px center;border:1px solid var(--line);border-radius:7px;height:30px;padding:0 24px 0 9px;cursor:pointer;min-width:0;width:100%}
select:focus,button:focus-visible,a:focus-visible{outline:2px solid var(--ink);outline-offset:2px}
.rm{width:28px;height:28px;border-radius:7px;border:1px solid transparent;background:none;cursor:pointer;color:var(--ink-3);font:16px/1 var(--sans)}
.rm:hover{border-color:var(--line);color:var(--ink)}
.b-row{display:flex;align-items:center;gap:12px;margin-top:12px}
.b-out{display:flex;align-items:center;gap:8px;margin-left:auto}
.b-out select{width:auto}
.tt{width:100%;border-collapse:collapse;margin-top:14px;font:400 13px var(--mono)}
.tt th{font-weight:500;font-size:10px;letter-spacing:.18em;text-transform:uppercase;color:var(--ink-3);text-align:left;padding:0 6px 6px}
.tt td{padding:6px;border-top:1px solid var(--line)}
.tt td:last-child{text-align:right;font-size:11px;letter-spacing:.12em;text-transform:uppercase}
.tt tr.fail td{color:var(--ink-3)}
.tt tr.fail td:last-child{color:var(--ink-2)}
.tt tr.pass td:last-child{color:var(--ink);font-weight:600}
.b-foot{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-top:14px;padding-top:14px;border-top:1px solid var(--line)}
.b-stats{display:flex;gap:26px}
.b-stats div{display:flex;flex-direction:column;gap:6px}
.b-stats span:last-child{font-size:20px;font-weight:600;letter-spacing:-.02em;font-variant-numeric:tabular-nums}
.b-go{display:flex;align-items:center;gap:12px}
.b-msg{font-size:12px;color:var(--ink-2);max-width:15em;text-align:right}
.win.solved .b-msg{color:var(--ink);font-weight:600}

@media (max-width:820px){
  .links{display:none}
  .nav{gap:10px;justify-content:space-between;padding:12px 16px}
  .nav .right .btn{height:36px;padding:0 13px;font-size:13px}
  .stick{padding:84px 16px 40px}
  .ch-top .stick{padding-top:92px}
  .ch-pot .stick{padding-top:48px}
  .hl{font-size:clamp(46px,13vw,72px)}
  .ch-hero .hl{font-size:clamp(56px,16.5vw,88px)}
  .ch-try .hl{font-size:clamp(46px,13vw,72px)}
  .copy{margin-top:16px;font-size:16px}
  .ca code{font-size:12px}
  .ch-try{height:auto}
  .ch-try .stick{position:relative;height:auto;min-height:100vh;padding-top:92px}
  .win{margin-top:16px}
  .win-body{grid-template-columns:1fr}
  .win-side{display:none}
  .win-meta{display:none}
  .win-main{padding:14px}
  .b-head{flex-direction:column;align-items:flex-start;gap:6px}
  .b-foot{flex-direction:column;align-items:stretch}
  .b-go{justify-content:space-between}
  .b-msg{text-align:left}
  .stat{padding:0 16px}
}

body.shot .txt{transition:none!important}

/* soft paper scrim behind pinned text so the die reads through mist around the words */
.txt::before{content:"";position:absolute;z-index:-1;left:50%;top:50%;width:min(1180px,100vw);height:135%;transform:translate(-50%,-50%);pointer-events:none;
  background:radial-gradient(closest-side,rgba(245,241,232,.9),rgba(245,241,232,.7) 55%,rgba(245,241,232,0))}
.on-die .txt::before{background:radial-gradient(closest-side,rgba(12,12,14,.55),rgba(12,12,14,.3) 55%,rgba(12,12,14,0))}
.ch-try .txt::before{height:170%;top:60%}