/* VisuaLearn
   Layout: a lab bench. Bars on the left, the code that moves them on the right, transport underneath. */
:root{
  --paper:#f6f7fb;
  --surface:#ffffff;
  --ink:#151a2d;
  --ink-2:#3b425c;
  --muted:#656b88;
  --line:#dfe2ec;
  --accent:#3451d1;
  --accent-soft:#e7ebfb;
  --bar:#b9c1dc;
  --cmp:#e9a400;
  --swap:#e0533d;
  --pivot:#8b4fd6;
  --done:#17917f;
  --font-display:'Bricolage Grotesque', 'Segoe UI', system-ui, sans-serif;
  --font-body:'Atkinson Hyperlegible', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-code:'JetBrains Mono', ui-monospace, Consolas, monospace;
  --r:12px;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){
  :root{
    --paper:#0f1220;
    --surface:#171b2e;
    --ink:#eef0f8;
    --ink-2:#c3c8dc;
    --muted:#9096b0;
    --line:#2a3049;
    --accent:#8196ff;
    --accent-soft:#1f2647;
    --bar:#4a5378;
    --cmp:#f2b928;
    --swap:#ff6f5a;
    --pivot:#b38cff;
    --done:#3cc3ad;
    color-scheme:dark;
  }
}

*,*::before,*::after{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--font-body);font-size:16px;line-height:1.55;-webkit-font-smoothing:antialiased}
a{color:var(--accent)}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{max-width:1180px;margin:0 auto;padding-left:max(20px, env(safe-area-inset-left, 0px));padding-right:max(20px, env(safe-area-inset-right, 0px))}
h1,h2{font-family:var(--font-display);font-weight:700;letter-spacing:-.02em;text-wrap:balance;margin:0}
.eyebrow{margin:0;font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:700}

/* header */
.top{position:sticky;top:0;z-index:5;background:color-mix(in srgb, var(--paper) 88%, transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.top-in{display:flex;align-items:center;justify-content:space-between;gap:16px;height:60px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-family:var(--font-display);font-size:20px;font-weight:500;letter-spacing:-.01em}
.brand b{font-weight:700}
.brand svg{width:28px;height:28px}
.b-bg{fill:var(--ink)} .b-1{fill:var(--bar)} .b-2{fill:var(--cmp)} .b-3{fill:var(--done)}
.nav{display:flex;gap:20px}
.nav a{color:var(--ink-2);text-decoration:none;font-size:15px}
.nav a:hover{color:var(--ink)}

/* hero */
.hero{padding-block:48px 28px;display:flex;flex-direction:column;gap:12px}
.hero h1{font-size:clamp(34px, 5.2vw, 58px);line-height:1.04}
.hero p{margin:0;max-width:62ch;color:var(--ink-2);font-size:18px}
.hero .eyebrow{font-size:12px;color:var(--muted)}

/* buttons, segmented */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border:1px solid var(--line);background:var(--surface);color:var(--ink);
  border-radius:9px;padding:8px 14px;font:inherit;font-size:15px;cursor:pointer;text-decoration:none;transition:border-color .15s, background .15s}
.btn:hover{border-color:var(--ink-2)}
.btn.icon{width:40px;height:40px;padding:0}
.btn.icon svg{width:18px;height:18px;fill:currentColor}
.btn.play{width:48px;height:48px;border-radius:50%;background:var(--ink);color:var(--paper);border-color:var(--ink)}
.btn.play:hover{background:var(--ink-2)}
.seg{display:flex;flex-wrap:wrap;gap:6px}
.seg button{border:1px solid var(--line);background:var(--surface);color:var(--ink-2);border-radius:999px;padding:7px 15px;font:inherit;font-size:15px;cursor:pointer}
.seg button:hover{border-color:var(--ink-2)}
.seg button[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:#fff}

/* visualiser */
.viz{display:flex;flex-direction:column;gap:16px;padding-bottom:56px}
.board{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:16px}
.stage,.code-card,.about-card,.controls{background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}
.stage{padding:18px;display:flex;flex-direction:column;gap:14px;min-width:0}
.stage-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px 20px;flex-wrap:wrap}
.note{margin:0;font-size:17px;min-height:2.6em;max-width:52ch;flex:1 1 280px}
.stats{display:flex;flex-wrap:wrap;gap:8px 18px;margin:0}
.stats div{display:flex;flex-direction:column}
.stats dt{font-size:11.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.stats dd{margin:0;font-family:var(--font-code);font-size:17px;font-variant-numeric:tabular-nums}

.bars{height:340px;display:flex;align-items:flex-end;gap:var(--gap, 4px);padding-top:8px;border-bottom:2px solid var(--line)}
.bar{flex:1 1 0;min-width:2px;background:var(--bar);border-radius:4px 4px 0 0;position:relative;transition:height .12s ease, background-color .12s ease, opacity .12s}
.bar span{position:absolute;left:50%;bottom:100%;transform:translateX(-50%);padding-bottom:3px;font-family:var(--font-code);font-size:12px;color:var(--muted);font-variant-numeric:tabular-nums}
.bar.done{background:var(--done)}
.bar.cmp{background:var(--cmp)}
.bar.swap{background:var(--swap)}
.bar.key{background:var(--accent)}
.bar.pivot{background:var(--pivot)}
.bar.dim{opacity:.32}
.bar.cmp span,.bar.swap span,.bar.key span,.bar.pivot span{color:var(--ink);font-weight:600}

.legend{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px 16px;font-size:13.5px;color:var(--ink-2)}
.legend li{display:flex;align-items:center;gap:6px}
.legend i{width:12px;height:12px;border-radius:3px;display:inline-block}
.k-cmp{background:var(--cmp)} .k-swap{background:var(--swap)} .k-key{background:var(--accent)} .k-pivot{background:var(--pivot)} .k-done{background:var(--done)}

.side{display:flex;flex-direction:column;gap:16px;min-width:0}
.code-card,.about-card{padding:16px;display:flex;flex-direction:column;gap:10px}
.code{list-style:none;margin:0;padding:0;font-family:var(--font-code);font-size:13.5px;counter-reset:ln;overflow-x:auto}
.code li{counter-increment:ln;display:flex;gap:12px;padding:3px 8px;border-radius:6px;white-space:pre;color:var(--ink-2)}
.code li::before{content:counter(ln);color:var(--muted);opacity:.7;min-width:1.4ch;text-align:right}
.code li.on{background:var(--accent-soft);color:var(--ink);box-shadow:inset 3px 0 0 var(--accent)}
.about-card p{margin:0;color:var(--ink-2);font-size:15px}
.about-card .eyebrow{color:var(--ink);font-size:13px}
.cx{display:grid;grid-template-columns:repeat(3, 1fr);gap:8px;margin:0}
.cx div{background:var(--paper);border-radius:8px;padding:7px 9px}
.cx dt{font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
.cx dd{margin:0;font-family:var(--font-code);font-size:14px}

.controls{padding:14px 16px;display:flex;flex-direction:column;gap:14px}
.transport{display:flex;align-items:center;gap:8px}
.transport input[type=range]{flex:1;min-width:80px;margin-left:8px}
input[type=range]{accent-color:var(--accent)}
.knobs{display:flex;flex-wrap:wrap;align-items:center;gap:12px 22px}
.knob{display:flex;align-items:center;gap:8px;font-size:14px;color:var(--ink-2)}
.knob input[type=range]{width:120px}
.knob output{font-family:var(--font-code);font-size:13px;min-width:2ch}
select,.custom input{font:inherit;font-size:15px;color:var(--ink);background:var(--paper);border:1px solid var(--line);border-radius:8px;padding:7px 10px}
.custom{display:flex;flex-wrap:wrap;align-items:center;gap:8px 10px;border-top:1px solid var(--line);padding-top:14px}
.custom label{font-size:14px;color:var(--ink-2)}
.custom input{flex:1 1 220px;font-family:var(--font-code)}
.err{color:var(--swap);font-size:14px;flex-basis:100%}
.err:empty{display:none}

/* sections */
.block{padding-block:40px;display:flex;flex-direction:column;gap:14px;border-top:1px solid var(--line)}
.block h2{font-size:clamp(26px, 3.4vw, 36px)}
.lede{margin:0;max-width:66ch;color:var(--ink-2)}
.fine{margin:0;max-width:66ch;color:var(--muted);font-size:14.5px}
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--r);background:var(--surface)}
.table{width:100%;border-collapse:collapse;font-size:15px;min-width:600px}
.table th,.table td{text-align:left;padding:11px 16px;border-bottom:1px solid var(--line)}
.table th{font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);font-weight:700}
.table td{font-family:var(--font-code);font-size:14px;font-variant-numeric:tabular-nums}
.table td:first-child{font-family:var(--font-body);font-size:15px;font-weight:700}
.table tr:last-child td{border-bottom:0}
.table tr.on td{background:var(--accent-soft)}
.soon{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fit, minmax(240px, 1fr));gap:12px}
.soon li{display:flex;flex-direction:column;gap:4px;padding:16px;border:1px dashed var(--line);border-radius:var(--r)}
.soon span{color:var(--ink-2);font-size:15px}

.foot{border-top:1px solid var(--line);padding-block:22px;color:var(--muted);font-size:14px}
.foot-in{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}
kbd{font-family:var(--font-code);font-size:12px;border:1px solid var(--line);border-bottom-width:2px;border-radius:4px;padding:0 5px;background:var(--surface)}

.lost{min-height:70vh;display:flex;flex-direction:column;justify-content:center;gap:12px}
.lost h1{font-size:clamp(32px, 5vw, 52px)}
.lost p{margin:0;color:var(--ink-2)}

/* header timer */
.timer{font-family:var(--font-code);font-size:13px;font-variant-numeric:tabular-nums;color:var(--ink-2);border:1px solid var(--line);border-radius:999px;padding:4px 10px;background:var(--surface);white-space:nowrap}
.timer.low{border-color:var(--cmp);color:var(--ink)}
.top-in .nav{margin-left:auto}

/* hero steps: a real sequence, so it's numbered */
.how{list-style:none;margin:10px 0 0;padding:0;display:grid;grid-template-columns:repeat(3, minmax(0,1fr));gap:12px;counter-reset:how;max-width:900px}
.how li{counter-increment:how;display:flex;flex-direction:column;gap:2px;padding:14px 16px 14px 54px;position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}
.how li::before{content:counter(how);position:absolute;left:16px;top:14px;width:26px;height:26px;border-radius:50%;display:grid;place-items:center;
  font-family:var(--font-display);font-weight:700;font-size:14px;background:var(--ink);color:var(--paper)}
.how li:last-child::before{background:var(--done);color:#fff}
.how b{font-family:var(--font-display);font-size:18px}
.how span{color:var(--ink-2);font-size:15px}

.viz-head{display:flex;flex-direction:column;gap:6px}
.viz-head h2{font-size:clamp(24px, 3vw, 32px)}
.viz-head p{margin:0;max-width:66ch;color:var(--ink-2)}

.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn.primary:hover{filter:brightness(1.08);border-color:var(--accent)}
.btn:disabled{opacity:.45;cursor:not-allowed}
.link{background:none;border:0;padding:4px 2px;font:inherit;font-size:14px;color:var(--muted);text-decoration:underline;text-underline-offset:3px;cursor:pointer}
.link:hover{color:var(--ink)}

/* predict question */
.quiz{flex:1 1 300px;display:flex;flex-direction:column;gap:10px;padding:12px 14px;border-radius:10px;background:var(--accent-soft);border:1px solid color-mix(in srgb, var(--accent) 35%, transparent)}
.quiz-q{margin:0;font-family:var(--font-display);font-size:19px;font-weight:500;line-height:1.3}
.quiz-opts{display:flex;flex-wrap:wrap;gap:8px}
.btn.opt{min-width:92px;font-weight:700;font-size:16px}
.btn.opt:disabled{opacity:.55;cursor:default}
.btn.opt.is-answer{opacity:1;border-color:var(--done);box-shadow:inset 0 0 0 1px var(--done)}
.quiz-foot{display:flex;justify-content:space-between;align-items:center;gap:10px}
.fb{margin:0;font-size:15px;color:var(--ink-2)}
.fb.right{color:var(--done);font-weight:700}
.fb.wrong{color:var(--swap);font-weight:700}

.done{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 16px;padding:12px 14px;border-radius:10px;background:color-mix(in srgb, var(--done) 12%, var(--surface));border:1px solid color-mix(in srgb, var(--done) 40%, transparent)}
.done p{margin:0;font-weight:700}

.switch{display:flex;align-items:center;gap:8px;font-size:14px;font-weight:700;color:var(--ink);cursor:pointer}
.switch input{width:18px;height:18px;accent-color:var(--accent)}

/* offline card */
.off-card{background:var(--surface);border:2px solid var(--ink);border-radius:16px;padding:24px;display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr);gap:20px 32px;
  grid-template-areas:"head head" "steps think" "steps tally" "actions actions"}
.off-head{grid-area:head;display:flex;flex-direction:column;gap:8px}
.off-head h2{font-size:clamp(28px, 4vw, 40px)}
.chips{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:8px}
.chips li{font-size:14px;padding:4px 12px;border-radius:999px;background:var(--paper);border:1px solid var(--line)}
.chips b{color:var(--muted);font-weight:700;margin-right:4px}
.off-steps{grid-area:steps;margin:0;padding-left:1.4em;display:flex;flex-direction:column;gap:10px;font-size:17px}
.off-steps li::marker{font-family:var(--font-display);font-weight:700;color:var(--accent)}
.off-think{grid-area:think;display:flex;flex-direction:column;gap:6px;padding:14px;border-radius:10px;background:var(--accent-soft)}
.off-think p:last-child,.tally p:not(.eyebrow){margin:0;font-size:15px}
.tally{grid-area:tally;display:flex;flex-direction:column;gap:6px}
.tally-box{height:72px;border:1.5px dashed var(--muted);border-radius:8px;
  background-image:repeating-linear-gradient(90deg, transparent 0 39px, var(--line) 39px 40px)}
.off-actions{grid-area:actions;display:flex;flex-wrap:wrap;align-items:center;gap:8px 14px;color:var(--muted);font-size:14px}

/* grown-ups */
.gu{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr);gap:24px}
.gu-why{display:flex;flex-direction:column;gap:12px}
.gu-why p{margin:0;max-width:62ch;color:var(--ink-2)}
.promises{margin:0;padding-left:1.2em;display:flex;flex-direction:column;gap:6px}
.promises li::marker{color:var(--done)}
.gu-set{display:flex;flex-direction:column;gap:10px;align-self:start;padding:16px;background:var(--surface);border:1px solid var(--line);border-radius:var(--r)}

/* rest screen */
.rest{position:fixed;inset:0;z-index:20;display:grid;place-items:center;padding:20px;background:color-mix(in srgb, var(--paper) 70%, transparent);backdrop-filter:blur(6px)}
.rest-card{max-width:480px;width:100%;background:var(--surface);border:2px solid var(--ink);border-radius:18px;padding:28px;box-shadow:0 20px 60px rgba(10,14,30,.25)}
.rest-card > div{display:flex;flex-direction:column;gap:12px}
.rest-card h2{font-size:30px}
.rest-card p{margin:0;color:var(--ink-2)}
.rest-actions{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-top:6px}
body.resting{overflow:hidden}

@media (max-width: 920px){
  .off-card{grid-template-columns:minmax(0,1fr);grid-template-areas:"head" "steps" "think" "tally" "actions"}
  .gu{grid-template-columns:minmax(0,1fr)}
  .how{grid-template-columns:minmax(0,1fr)}
}
@media (max-width: 920px){
  .board{grid-template-columns:minmax(0,1fr)}
  .bars{height:280px}
}
@media (max-width: 560px){
  .nav{display:none}
  .timer{margin-left:auto}
  .off-card{padding:18px}
  .hero{padding-block:32px 20px}
  .hero p{font-size:16.5px}
  .bars{height:230px}
  .stats{gap:14px}
  .cx{grid-template-columns:repeat(2, 1fr)}
  .knob input[type=range]{width:96px}
}
/* print: only the offline activity, in black on white */
@media print{
  :root{--paper:#fff;--surface:#fff;--ink:#000;--ink-2:#222;--muted:#555;--line:#999;--accent:#000;--accent-soft:#f1f1f1;color-scheme:light}
  body{background:#fff;font-size:13pt}
  .top,.foot,.rest,.no-print,main > section:not(#offline){display:none!important}
  #offline{border:0;padding:0}
  .off-card{border:2px solid #000;box-shadow:none;break-inside:avoid}
  .tally-box{height:110px}
}
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  .bar{transition:none}
}

/* ---------- lesson pages ---------- */
.lesson-top{padding-top:32px}
.viz-head h1{font-size:clamp(28px, 4vw, 44px);line-height:1.08}
.crumbs a{color:inherit;text-decoration:none}
.crumbs a:hover{color:var(--ink);text-decoration:underline}
.goal{margin:0;font-size:16px;color:var(--ink-2)}
.goal b{font-family:var(--font-code);font-size:20px;color:var(--ink);background:var(--accent-soft);border-radius:6px;padding:1px 8px;margin-left:4px}
.custom .num{flex:0 0 84px}
.legend i.k-closed{background:var(--ink-2)}
.legend i.k-out,.legend i.k-seen{background:var(--line)}
.legend i.k-wall{background:var(--ink)}
.legend i.k-rest{background:transparent;border:1.5px dashed var(--muted)}

/* searching: closed boxes */
.boxes{display:grid;grid-template-columns:repeat(auto-fill, minmax(52px, 1fr));gap:8px;min-height:180px;align-content:center}
.boxes.small{grid-template-columns:repeat(auto-fill, minmax(42px, 1fr));gap:6px}
.boxes.tiny{grid-template-columns:repeat(auto-fill, minmax(34px, 1fr));gap:4px}
.box{aspect-ratio:3/4;border-radius:8px;background:var(--ink-2);color:var(--paper);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;
  transition:background-color .15s, opacity .15s, transform .15s}
.box b{font-family:var(--font-code);font-size:18px;font-variant-numeric:tabular-nums}
.box small{font-size:10.5px;opacity:.7}
.boxes.tiny .box b{font-size:13px}
.boxes.tiny .box small{display:none}
.box.open{background:var(--surface);color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--line)}
.box.cur{background:var(--cmp);color:#151a2d;transform:translateY(-4px)}
.box.found{background:var(--done);color:#fff;transform:translateY(-4px)}
.box.out{opacity:.28}

/* mazes */
.maze{display:grid;grid-template-columns:repeat(var(--cols, 11), minmax(0, 1fr));gap:3px;max-width:620px;width:100%;margin:0 auto}
.cell{aspect-ratio:1;border-radius:5px;background:var(--paper);box-shadow:inset 0 0 0 1px var(--line);display:grid;place-items:center;
  font-family:var(--font-code);font-size:clamp(10px, 1.6vw, 14px);font-weight:600;color:#151a2d;transition:background-color .12s}
.cell.wall{background:var(--ink);box-shadow:none}
.cell.wait{background:var(--cmp)}
.cell.seen{background:var(--line)}
.cell.cur{background:var(--accent);color:#fff}
.cell.path{background:var(--done);color:#fff}
.cell.home,.cell.school{font-size:clamp(14px, 2.4vw, 20px);color:var(--ink)}
.cell.home.path,.cell.school.path,.cell.home.cur,.cell.school.cur{color:#fff}

/* math: sieve grid */
.sieve{display:grid;grid-template-columns:repeat(10, minmax(0, 1fr));gap:4px;max-width:560px;width:100%;margin:0 auto}
.sieve div{aspect-ratio:1.25;border-radius:6px;display:grid;place-items:center;background:var(--paper);box-shadow:inset 0 0 0 1px var(--line);
  font-family:var(--font-code);font-size:clamp(11px, 1.7vw, 15px);font-variant-numeric:tabular-nums;transition:background-color .12s}
.sieve .one{color:var(--muted);opacity:.5}
.sieve .crossed{color:var(--muted);text-decoration:line-through;opacity:.45}
.sieve .crossed.mult{opacity:.8;background:color-mix(in srgb, var(--accent) 10%, var(--paper))}
.sieve .prime{background:var(--done);color:#fff;font-weight:600;box-shadow:none}
.sieve .cur{background:var(--accent);color:#fff;font-weight:600;box-shadow:none;opacity:1;text-decoration:none}
.sieve .hit{background:var(--swap);color:#fff;opacity:1;box-shadow:none}

/* math: Euclid rectangle */
.euclid{display:flex;justify-content:center}
.euclid svg{width:100%;max-height:340px}
.eu-frame{fill:var(--paper);stroke:var(--line);stroke-width:1.5;vector-effect:non-scaling-stroke}
.eu-sq{stroke:var(--surface);stroke-width:2;vector-effect:non-scaling-stroke}
.eu-sq.r0{fill:var(--cmp)} .eu-sq.r1{fill:var(--done)} .eu-sq.r2{fill:var(--accent)} .eu-sq.r3{fill:var(--pivot)}
.eu-sq.now{stroke:var(--ink);stroke-width:3}
.eu-rest{fill:none;stroke:var(--muted);stroke-width:1.5;stroke-dasharray:6 4;vector-effect:non-scaling-stroke}
.eu-label{fill:#fff;font-family:var(--font-code);font-weight:600;text-anchor:middle;dominant-baseline:central}

/* offline: squared paper */
.grid-box{height:160px;border:1.5px dashed var(--muted);border-radius:8px;
  background-image:linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);background-size:20px 20px}

/* ---------- home ---------- */
.cards{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fit, minmax(240px, 1fr));gap:14px}
.card{height:100%;display:flex;flex-direction:column;gap:6px;padding:18px;border-radius:14px;background:var(--surface);border:1px solid var(--line);
  color:var(--ink);text-decoration:none;transition:border-color .15s, transform .15s}
.card:hover{border-color:var(--ink-2);transform:translateY(-2px)}
.card svg{width:100%;height:72px;margin-bottom:6px;background:var(--paper);border-radius:10px;padding:6px}
.card b{font-family:var(--font-display);font-size:21px}
.card span{color:var(--ink-2);font-size:15px}
.card small{margin-top:auto;padding-top:8px;color:var(--done);font-weight:700;font-size:13.5px}
.i-bar{fill:var(--bar)} .i-cmp{fill:var(--cmp)} .i-done{fill:var(--done)} .i-key{fill:var(--accent)} .i-pivot{fill:var(--pivot)}
.i-out{fill:var(--line)} .i-wall{fill:var(--ink)} .i-rest{fill:none;stroke:var(--muted);stroke-dasharray:4 3}
.i-grid rect{fill:var(--surface);stroke:var(--paper);stroke-width:2}
.i-grid rect.i-wall{fill:var(--ink)} .i-grid rect.i-done{fill:var(--done)} .i-grid rect.i-cmp{fill:var(--cmp)}
.i-line{fill:none;stroke:var(--ink-2);stroke-width:2.5;stroke-linecap:round;stroke-linejoin:round}
.sub{font-family:var(--font-display);font-size:20px;margin:14px 0 0}
.plan{margin:0;padding-left:1.4em;display:flex;flex-direction:column;gap:8px;color:var(--ink-2)}
.plan b{color:var(--ink)}
.plan li::marker{font-family:var(--font-display);font-weight:700;color:var(--accent)}
@media (max-width: 560px){
  .boxes{grid-template-columns:repeat(auto-fill, minmax(40px, 1fr));gap:5px}
  .maze{gap:2px}
  .sieve{gap:3px}
}
@media (prefers-reduced-motion: reduce){
  .box,.cell,.sieve div,.card{transition:none}
}