@font-face{font-family:Instrument;src:url('../../assets/fonts/instrument-sans-latin-400-normal.woff2');font-display:swap}
@font-face{font-family:Instrument;src:url('../../assets/fonts/instrument-sans-latin-600-normal.woff2');font-weight:600;font-display:swap}
@font-face{font-family:Anybody;src:url('../../assets/fonts/anybody-var.woff2');font-weight:100 900;font-display:swap}
@font-face{font-family:JetBrains;src:url('../../assets/fonts/jetbrains-mono-latin-400-normal.woff2');font-display:swap}
:root{--app-accent:#ff8a1f;--accent-text:#ff9d43;--bg:#0b1015;--panel:#111920;--raised:#1d2832;--line:#2b3741;--fg:#ecf0f2;--muted:#a3afb9;--good:#7edca0;--font:Instrument,system-ui,sans-serif;--display:Anybody,system-ui,sans-serif;--mono:JetBrains,ui-monospace,monospace}
:root[data-theme=light]{--bg:#f4f2ee;--panel:#fff;--raised:#eeeae4;--line:#d8d3cb;--fg:#1b2933;--muted:#5c6870;--accent-text:#a64c00;--good:#1f8a4f}
body{font-family:var(--font);font-size:15px}
button{transition:background .15s,border-color .15s;touch-action:manipulation}
button.primary,button.primary[aria-pressed=true]{background:var(--app-accent);color:#241204;border-color:var(--app-accent)}button.primary:hover{background:#ffa24b}
button[aria-pressed=true]{border-color:var(--app-accent);background:color-mix(in srgb,var(--app-accent) 11%,var(--panel))}
button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible,canvas:focus-visible{outline:2px solid var(--app-accent);outline-offset:3px}
input[type=range]{accent-color:var(--app-accent)}output{color:var(--accent-text)}
select{width:auto}
.app-header{padding:12px max(24px,calc((100vw - 1400px)/2));min-height:70px}.app-header strong{font-size:12px;letter-spacing:.13em;text-align:center}.app-header strong span{margin-left:12px;color:var(--muted);font:10px var(--mono);letter-spacing:.08em}
.app-main{max-width:1440px;padding:38px 24px 28px}
.eyebrow{font:10px var(--mono);color:var(--accent-text);letter-spacing:.11em;text-transform:uppercase}

/* hero */
.intro{display:flex;align-items:center;justify-content:space-between;gap:30px;padding:0 0 32px}
.intro h1{font:650 clamp(36px,4.8vw,65px)/1.05 var(--display);letter-spacing:-.045em}.intro h1 span{color:var(--accent-text)}
.intro-note{display:flex;align-items:center;gap:22px;max-width:470px}.intro-note p{color:var(--muted);font-size:14px;line-height:1.7}
.intro-ring{width:104px;height:104px;flex:none}.intro-ring>circle{fill:none;stroke:var(--line);stroke-width:9}.intro-ring .dots circle{fill:#62d9ef}.intro-ring .jam circle{fill:#ff5468}.intro-ring .jam circle:first-child{fill:var(--app-accent)}.intro-ring .arrow{fill:none;stroke:var(--accent-text);stroke-width:2.5;stroke-linecap:round;stroke-dasharray:4 4;marker-end:none}
:root[data-theme=light] .intro-ring .dots circle{fill:#0080a8}

/* question cards */
.section-label{display:flex;justify-content:space-between;gap:12px;font:10px var(--mono);letter-spacing:.11em;color:var(--muted);margin-bottom:10px;text-transform:uppercase}
.questions{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:10px;margin-bottom:20px}
.questions button{text-align:left;min-width:0;padding:15px 16px 16px;background:var(--panel);border-radius:12px;position:relative;display:flex;flex-direction:column;align-items:flex-start;justify-content:flex-start}
.questions button[aria-pressed=true]:after{content:'';position:absolute;inset:auto 16px -1px;height:3px;background:var(--app-accent);border-radius:3px}
.questions span{display:block;font:9px var(--mono);color:var(--accent-text);letter-spacing:.06em;margin-bottom:9px}
.questions strong{font-size:15px;line-height:1.3;display:block}
.questions small{display:block;margin-top:6px;font-size:11px;line-height:1.5;color:var(--muted);font-weight:400}

/* bench */
.bench{border:1px solid var(--line);border-radius:17px;overflow:hidden;background:var(--panel);scroll-margin-top:12px}
.bench:focus{outline:none}
.bench-toolbar{padding:12px 18px;display:flex;align-items:center;gap:14px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.transport{display:flex;gap:8px}.transport button{font-size:12px}#play{min-width:92px}
.time-speed{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);margin-left:auto}.time-speed select{min-height:40px;padding:6px 10px;font-size:14px}
.clock{display:flex;flex-direction:column;align-items:flex-end;min-width:92px}.clock small{font:9px var(--mono);color:var(--muted);letter-spacing:.1em}.clock output{font:500 18px var(--mono)}
.stage{display:grid;grid-template-columns:minmax(0,.92fr) minmax(0,1.08fr)}
.panel{margin:0;min-width:0;display:flex;flex-direction:column}
.ring-panel{border-right:1px solid var(--line)}
.panel-head{display:flex;justify-content:space-between;align-items:flex-end;gap:14px;padding:20px 22px 0}
.panel-head h2{font:600 21px var(--font);letter-spacing:-.03em;margin-top:6px}
.panel-head .hint{font-size:12px;color:var(--muted);text-align:right}
.ring-wrap{position:relative;aspect-ratio:1/1;max-height:560px;width:100%}
#ringCanvas{position:absolute;inset:0;width:100%;height:100%;display:block;cursor:pointer;touch-action:manipulation}
.legend-bar{display:flex;align-items:center;gap:14px;flex-wrap:wrap;padding:0 22px 18px;font-size:11px;color:var(--muted)}
.legend-label{font:9px var(--mono);letter-spacing:.1em}
.legend-scale{display:flex;flex-direction:column;gap:3px;flex:1 1 160px;max-width:280px}.legend-scale i{display:block;height:8px;border-radius:5px;background:linear-gradient(90deg,#ff5468,#ff8a1f 22%,#ffcc54 48%,#7edca0 74%,#62d9ef)}
.legend-scale span{display:flex;justify-content:space-between;font:10px var(--mono)}.legend-scale b{font-weight:400}
.legend-key{display:flex;align-items:center;gap:6px}.brake-light{display:inline-block;width:10px;height:5px;border-radius:2px;background:#ff2d4a;box-shadow:0 0 6px #ff2d4a}
.tabs{display:flex;padding:4px;border:1px solid var(--line);border-radius:11px;background:var(--bg);gap:4px}
.tabs button{background:transparent;border-color:transparent;white-space:nowrap;min-height:38px;padding:6px 12px;font-size:12px}
.tabs button[aria-pressed=true]{background:var(--app-accent);color:#251406}
.plot-wrap{position:relative;flex:1 1 auto;min-height:360px;margin:16px 18px 0 10px}
#plotCanvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.plot-note{font-size:12px;color:var(--muted);padding:12px 22px 18px;line-height:1.6}.plot-note em{color:var(--fg);font-style:normal;font-weight:600}
.readings{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:1px;background:var(--line);border-top:1px solid var(--line)}
.readings>div{background:var(--panel);padding:15px 20px;min-width:0}
.readings span{display:block;font:9px var(--mono);color:var(--muted);letter-spacing:.1em;text-transform:uppercase}
.readings strong{display:block;font:500 26px/1.2 var(--mono);margin-top:5px;font-variant-numeric:tabular-nums;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.readings small{display:block;font-size:11px;color:var(--muted);margin-top:2px}
.wave-reading strong{color:var(--accent-text)}
.story{min-height:128px;display:flex;gap:16px;align-items:flex-start;padding:18px 22px 20px;border-top:1px solid var(--line);background:color-mix(in srgb,var(--app-accent) 5%,var(--panel))}
.story-mark{flex:none;width:12px;height:12px;border-radius:50%;margin-top:4px;background:var(--good);box-shadow:0 0 0 5px color-mix(in srgb,var(--good) 20%,transparent)}
.story-mark.warn{background:var(--app-accent);box-shadow:0 0 0 5px color-mix(in srgb,var(--app-accent) 22%,transparent)}
.story-mark.bad{background:#ff5468;box-shadow:0 0 0 5px rgba(255,84,104,.22)}
.story h3{font:600 18px/1.35 var(--font);letter-spacing:-.02em;margin:5px 0 4px}
.story p:last-child{font-size:13px;color:var(--muted);max-width:900px}

/* desk */
.desk{display:grid;grid-template-columns:1.1fr 1fr 1fr;gap:16px;margin-top:20px}
.card{border:1px solid var(--line);border-radius:14px;padding:22px;background:var(--panel);min-width:0}
.card h2{font:600 22px var(--font);letter-spacing:-.03em;margin:6px 0 14px}
.card>p{font-size:13px;color:var(--muted)}
.field{margin-top:16px}.field:first-of-type{margin-top:0}
.range-row{display:flex;align-items:center;justify-content:space-between;gap:10px}.range-row label{color:var(--fg);font-size:13px}.range-row output{font-size:13px}
.field input[type=range]{min-height:34px}
.field-note{font-size:11px;color:var(--muted);margin-top:-2px}
.brake-row{display:flex;gap:8px;margin-top:14px}.brake-row select{flex:1;min-width:0}.brake-row button{flex:1.4}
.car-facts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;background:var(--line);border:1px solid var(--line);border-radius:10px;overflow:hidden;margin:14px 0}
.car-facts div{background:var(--bg);padding:9px 11px}.car-facts dt{font:9px var(--mono);color:var(--muted);letter-spacing:.08em;text-transform:uppercase}.car-facts dd{margin:2px 0 0;font:500 14px var(--mono);white-space:nowrap}
.check{display:flex;gap:10px;align-items:center;font-size:13px;color:var(--fg);min-height:44px;cursor:pointer}.check input{width:18px;height:18px;accent-color:var(--app-accent);flex:none}
#statusLine{min-height:18px;margin-top:4px}
.predict{margin-top:16px;padding-top:16px;border-top:1px solid var(--line)}.predict h3{font-size:14px;margin:6px 0 10px}
.predict-choices{display:grid;gap:6px}.predict-choices button{text-align:left;font-weight:500;min-height:40px;padding:8px 12px;background:var(--bg)}
.predict-choices button.right{border-color:var(--good);background:color-mix(in srgb,var(--good) 14%,var(--bg))}.predict-choices button.wrong{border-color:#ff5468}
.predict-result{font-size:12px;color:var(--muted);margin-top:8px;min-height:18px}
.challenge-list{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.challenge{border:1px solid var(--line);border-radius:11px;padding:13px 14px;background:var(--bg)}
.challenge-head{display:flex;gap:10px;align-items:flex-start}
.challenge-tick{flex:none;width:22px;height:22px;border-radius:50%;border:1.5px solid var(--line);display:grid;place-items:center;font-size:12px;color:transparent;margin-top:1px}
.challenge.done{border-color:color-mix(in srgb,var(--good) 55%,var(--line))}.challenge.done .challenge-tick{background:var(--good);border-color:var(--good);color:#06140c}
.challenge strong{font-size:14px;display:block}.challenge p{font-size:12px;color:var(--muted);margin-top:3px}
.challenge .progress{font:10px var(--mono);color:var(--accent-text);margin-top:6px;letter-spacing:.04em}
.challenge.done .progress{color:var(--good)}
.challenge details{margin-top:6px;font-size:12px;color:var(--muted)}.challenge summary{cursor:pointer;color:var(--fg);font-size:12px;min-height:28px;display:flex;align-items:center}
.link-button{background:none;border:none;color:var(--muted);font-size:11px;padding:0;min-height:36px;margin-top:6px;text-decoration:underline;text-underline-offset:3px}.link-button:hover{background:none;color:var(--fg)}

/* learn */
.learn{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin-top:20px;align-items:start}
.learn-card{border:1px solid var(--line);border-radius:14px;background:color-mix(in srgb,var(--panel) 65%,var(--bg));min-width:0}
.learn-card summary{list-style:none;cursor:pointer;padding:18px 22px;display:flex;flex-direction:column;gap:5px;position:relative;border-radius:14px}
.learn-card summary::-webkit-details-marker{display:none}
.learn-card summary:after{content:'+';position:absolute;right:20px;top:50%;transform:translateY(-50%);font:400 22px var(--mono);color:var(--accent-text)}
.learn-card[open] summary:after{content:'−'}
.learn-card summary strong{font-size:17px}
.learn-card>p,.learn-card>ul{padding:0 22px;font-size:13px;color:var(--muted);line-height:1.75;margin:0 0 12px}
.learn-card>ul{padding-left:40px}.learn-card>:last-child{margin-bottom:20px}
.learn-card b,.learn-card em{color:var(--fg)}.learn-card code{font:12px var(--mono);color:var(--accent-text)}.learn-card a{color:var(--fg)}
.app-footer span a{color:var(--fg)}
.noscript{max-width:700px;margin:20px auto;padding:0 20px}

@media(max-width:1180px){.questions{grid-template-columns:repeat(3,minmax(0,1fr))}.desk{grid-template-columns:1fr 1fr}.challenges{grid-column:1/-1}.challenge-list{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:980px){.stage{grid-template-columns:minmax(0,1fr)}.ring-panel{border-right:0;border-bottom:1px solid var(--line)}.ring-wrap{max-width:560px;margin:0 auto}.plot-wrap{min-height:320px}.readings{grid-template-columns:repeat(3,minmax(0,1fr))}.learn{grid-template-columns:minmax(0,1fr)}.intro{flex-direction:column;align-items:flex-start;gap:18px}}
@media(max-width:760px){.desk{grid-template-columns:minmax(0,1fr)}.challenge-list{grid-template-columns:minmax(0,1fr)}.questions{grid-template-columns:repeat(2,minmax(0,1fr))}.app-header strong span{display:none}}
@media(max-width:520px){
  .app-main{padding:24px 12px 24px}.app-header{padding-inline:14px}.app-header strong{font-size:10px;letter-spacing:.1em}
  .intro{padding-bottom:22px}.intro h1{font-size:40px}.intro-ring{width:72px;height:72px}.intro-note{gap:14px}.intro-note p{font-size:13px}
  .section-label span:last-child{display:none}
  .questions{gap:8px}.questions button{padding:12px 12px 13px}.questions strong{font-size:13px}.questions small{font-size:10.5px}
  .bench-toolbar{padding:10px 12px;gap:10px}.transport{flex:1 1 100%}.transport button{flex:1;padding-inline:8px}.time-speed{margin-left:0}
  .panel-head{padding:16px 14px 0;flex-wrap:wrap;align-items:flex-start}.panel-head .hint{text-align:left}
  .legend-bar{padding:0 14px 14px}.plot-wrap{margin:12px 8px 0 4px;min-height:280px}.plot-note{padding:10px 14px 14px}
  .readings{grid-template-columns:repeat(2,minmax(0,1fr))}.readings>div{padding:12px 14px}.readings strong{font-size:21px}.wave-reading{grid-column:1/-1}
  .story{padding:16px 14px;min-height:200px}.story h3{font-size:16px}
  .card{padding:18px}.learn-card summary{padding:16px 18px}.learn-card>p,.learn-card>ul{padding-inline:18px}.learn-card>ul{padding-left:34px}
}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important}}
.steady{margin-top:18px;padding-top:16px;border-top:1px solid var(--line)}.steady .car-facts{margin:8px 0 8px}
.learn-card summary .eyebrow{margin:0}

/* ---------- relayout (2026-10): driver and brake controls sit in a rail beside the road ---------- */
.bench{overflow:clip}
.rail{min-width:0;display:flex;flex-direction:column;border-left:1px solid var(--line);background:color-mix(in srgb,var(--bg) 35%,var(--panel))}
.rail-group{padding:14px 18px 16px;border-bottom:1px solid var(--line)}.rail-group:last-child{border-bottom:0}
.rail-group>.eyebrow{margin-bottom:10px}
.rail .field{margin-top:8px}.rail .field:first-of-type{margin-top:0}
.rail .field input[type=range]{display:block;min-height:30px;height:30px;margin:0}
.rail .field-note{margin-top:0;line-height:1.45}
.rail .rail-intro{margin:0 0 4px}
.rail .brake-row{margin-top:8px}.rail .brake-row select{min-height:40px;font-size:14px;padding:6px 10px}
.rail .car-facts{margin:10px 0 4px}
.rail .check{min-height:40px;font-size:12px;line-height:1.4}
.desk{grid-template-columns:minmax(0,1fr) minmax(0,1.3fr)}
.balance .steady{margin-top:0;padding-top:0;border-top:0}
@media(min-width:1100px){
  .stage{grid-template-columns:minmax(0,.9fr) minmax(0,1.05fr) 300px}
  .bench-toolbar{padding:8px 16px}
  .panel-head{padding:12px 18px 0}.panel-head h2{font-size:19px;margin-top:4px}
  .ring-wrap{max-height:clamp(340px,calc(100vh - 450px),560px)}
  .legend-bar{padding:0 18px 12px}
  .plot-wrap{margin-top:10px;min-height:300px}.plot-note{padding:8px 18px 12px}
  .readings>div{padding:10px 18px 11px}.readings strong{font-size:21px;margin-top:2px}
}
@media(min-width:1100px) and (max-height:1050px){
  .intro{padding-bottom:22px}
  .questions{gap:8px;margin-bottom:14px}.questions button{padding:10px 13px 11px}.questions span{margin-bottom:5px}
  .questions strong{font-size:13.5px}.questions small{display:none}
}
@media(max-width:1180px){.challenges{grid-column:auto}.challenge-list{grid-template-columns:minmax(0,1fr)}}
@media(min-width:761px) and (max-width:1099px){
  .stage{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .rail{grid-column:1/-1;flex-direction:row;border-left:0;border-top:1px solid var(--line)}
  .rail-group{flex:1;border-bottom:0}.rail-group+.rail-group{border-left:1px solid var(--line)}
}
@media(max-width:980px) and (min-width:761px){.ring-panel{border-bottom:0}.ring-wrap{max-width:none}}
/* phones: the ring stays pinned at the top while the driver controls scroll under it */
@media(max-width:760px){
  .stage{display:flex;flex-direction:column}
  .ring-panel{display:contents}
  .ring-wrap{position:sticky;top:0;z-index:5;aspect-ratio:auto;height:min(300px,36vh);max-width:none;background:var(--panel);border-bottom:1px solid var(--line);box-shadow:0 8px 14px -8px #0005}
  .legend-bar{padding-top:10px}
  .rail{order:1;border-left:0;border-top:1px solid var(--line)}
  .plot-panel{order:2;border-top:1px solid var(--line)}
  .desk{grid-template-columns:minmax(0,1fr)}
}
/* readings now sit directly under the toolbar, above the road */
.readings{border-top:0;border-bottom:1px solid var(--line)}