@font-face{font-family:Instrument;src:url('../../assets/fonts/instrument-sans-latin-400-normal.woff2') format('woff2');font-display:swap}
@font-face{font-family:Instrument;src:url('../../assets/fonts/instrument-sans-latin-600-normal.woff2') format('woff2');font-weight:600;font-display:swap}
@font-face{font-family:Anybody;src:url('../../assets/fonts/anybody-var.woff2') format('woff2');font-weight:100 900;font-display:swap}
@font-face{font-family:JetBrains;src:url('../../assets/fonts/jetbrains-mono-latin-400-normal.woff2') format('woff2');font-display:swap}

:root{--app-accent:#ff8a1f;--accent-text:#ff9d43;--bg:#0b1015;--panel:#111920;--raised:#1d2832;--line:#2b3741;--fg:#ecf0f2;--muted:#a3afb9;
  --font:Instrument,system-ui,sans-serif;--display:Anybody,system-ui,sans-serif;--mono:JetBrains,ui-monospace,monospace;
  --c0:#5fd4ec;--c1:#ff8a1f;--field-mid:#141d25;--boundary:#ffffff;--dot-edge:#f4f7f9;--field-bg:#0d141a}
:root[data-theme=light]{--bg:#f4f2ee;--panel:#fff;--raised:#eeeae4;--line:#d8d3cb;--fg:#1b2933;--muted:#5c6870;--accent-text:#a64c00;
  --c0:#0b8fa8;--c1:#ea6f00;--field-mid:#f7f5f1;--boundary:#1b2933;--dot-edge:#ffffff;--field-bg:#ece8e1}

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,a:focus-visible{outline:2px solid var(--app-accent);outline-offset:3px}
input[type=range]{accent-color:var(--app-accent)}
output{color:var(--accent-text)}
:root[data-theme=light] output,:root[data-theme=light] .eyebrow{color:var(--accent-text)}

.app-header{max-width:none;padding:12px max(24px,calc((100vw - 1400px)/2));min-height:70px}
.app-header strong{font-size:12px;letter-spacing:.13em}
.app-header strong span{margin-left:12px;color:var(--muted);font:10px var(--mono)}
.app-main{max-width:1440px;padding:38px 24px 28px}
.eyebrow{font:10px var(--mono);color:var(--accent-text);letter-spacing:.11em;margin-bottom:8px}

/* 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:24px;max-width:470px}
.intro-note p{color:var(--muted);font-size:14px;line-height:1.7}
.intro-glyph{width:96px;height:96px;flex:none;color:var(--accent-text);transform:rotate(-8deg)}

/* Question cards */
.presets{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:10px;margin-bottom:20px}
.presets button{text-align:left;min-width:0;padding:14px 15px 15px;background:var(--panel);border-radius:12px;position:relative;display:flex;flex-direction:column;align-items:flex-start;justify-content:flex-start}
.presets button[aria-pressed=true]:after{content:'';position:absolute;inset:auto 15px -1px;height:3px;background:var(--app-accent);border-radius:3px}
.presets span{display:block;font:9px var(--mono);color:var(--accent-text);letter-spacing:.06em;margin-bottom:9px}
.presets strong{font-size:15px;line-height:1.3;display:block}
.presets small{display:block;margin-top:5px;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-toolbar{padding:12px 18px;display:flex;align-items:center;gap:14px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.tabs{padding:4px;border:1px solid var(--line);border-radius:11px;background:var(--bg);flex-wrap:nowrap;display:flex;gap:4px}
.tabs button{background:transparent;border-color:transparent;white-space:nowrap;font-size:12px}
.tabs button[aria-pressed=true]{background:var(--app-accent);color:#251406}
.view-toggles{display:flex;gap:16px;margin-right:auto}
.view-toggles label,.speed{display:flex;align-items:center;gap:8px;min-height:44px;font-size:12px;color:var(--fg);cursor:pointer}
.view-toggles input{accent-color:var(--app-accent);width:16px;height:16px;margin:0}
.bench-actions{display:flex;gap:8px}
.bench-actions button{font-size:12px}

.meter-strip{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-bottom:1px solid var(--line)}
.meter-strip>div{padding:14px 22px;border-right:1px solid var(--line);min-width:0}
.meter-strip>div:last-child{border-right:0}
.meter-strip span{display:block;font:9px var(--mono);letter-spacing:.1em;color:var(--muted)}
.meter-strip strong{display:block;font:500 24px var(--mono);letter-spacing:-.04em;margin:4px 0 1px;font-variant-numeric:tabular-nums}
.meter-strip strong.accent{color:var(--accent-text)}
.meter-strip strong.warn{color:var(--danger)}
.meter-strip small{display:block;color:var(--muted);font-size:11px}

.work-area{display:grid;grid-template-columns:272px minmax(0,1fr) 340px;grid-template-areas:"controls stage side" "insight insight insight"}
.controls{grid-area:controls;border-right:1px solid var(--line);padding:20px;display:grid;gap:22px;align-content:start;background:color-mix(in srgb,var(--bg) 35%,var(--panel))}
.stage{grid-area:stage;min-width:0;display:flex;flex-direction:column}
.side{grid-area:side;border-left:1px solid var(--line);display:flex;flex-direction:column;min-width:0}

.block-head{flex-direction:column;gap:8px}.block-head .legend{justify-content:flex-start}.stage-head,.block-head{display:flex;justify-content:space-between;align-items:flex-start;gap:14px;padding:18px 22px 12px}
.stage-head h2,.block-head h2,.ctrl-group h2{font:600 19px/1.2 var(--font);letter-spacing:-.03em}
.legend{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px 14px;font-size:11px;color:var(--muted);justify-content:flex-end}
.legend li{display:flex;align-items:center;gap:6px;white-space:nowrap}
.legend i,i.dot{margin:0}i.dot{display:inline-block;width:9px;height:9px;border-radius:50%;flex:none}
i.dot.c0{background:var(--c0)}i.dot.c1{background:var(--c1)}
i.ring{display:inline-block;width:10px;height:10px;border-radius:50%;border:2px solid var(--muted);background:transparent!important}
i.diamond{border-radius:1px!important;display:inline-block;width:8px;height:8px;background:var(--muted);transform:rotate(45deg);outline:1.5px solid var(--fg);outline-offset:0}
i.line-train,i.line-val{display:inline-block;width:20px;height:0!important;border-radius:0!important;background:none!important;border-top:2px solid var(--fg)}
i.line-val{border-top:2.5px dashed var(--c1)}

.field-wrap{position:relative;margin:0 22px;align-self:center;width:calc(100% - 44px);max-width:min(560px,62vh);aspect-ratio:1;border-radius:12px;overflow:hidden;background:var(--field-bg);border:1px solid var(--line)}
#field{display:block;width:100%;height:100%;cursor:crosshair;touch-action:manipulation}
#field.inspect{cursor:default}
.axis-label{position:absolute;font:10px var(--mono);color:var(--fg);opacity:.55;pointer-events:none}
.ax-x{right:8px;top:calc(50% + 4px)}.ax-y{left:calc(50% + 6px);top:6px}
.probe-line{font:12px var(--mono);color:var(--muted);text-align:center;padding:10px 22px 4px;min-height:38px;font-variant-numeric:tabular-nums}
.probe-line b{color:var(--fg);font-weight:500}
.probe-line .p1{color:var(--accent-text)}.probe-line .p0{color:var(--c0)}

.transport{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;padding:14px 22px;margin-top:auto;border-top:1px solid var(--line);background:color-mix(in srgb,var(--bg) 40%,var(--panel))}
.transport-buttons{display:flex;gap:7px;flex-wrap:wrap}
.transport-buttons button{font-size:12px}
#play{min-width:118px;display:inline-flex;align-items:center;justify-content:center;gap:9px}
.play-icon{width:0;height:0;border-left:10px solid currentColor;border-top:6px solid transparent;border-bottom:6px solid transparent}
#play[aria-pressed=true] .play-icon{width:10px;height:12px;border:0;border-left:3px solid currentColor;border-right:3px solid currentColor}
.speed select{width:auto;min-width:140px}

.panel-block{border-bottom:1px solid var(--line);display:flex;flex-direction:column}
.panel-block:last-child{border-bottom:0;flex:1}
#network{display:block;width:100%;height:330px}
#loss{display:block;width:100%;height:190px;margin-bottom:10px}
.block-note{font-size:11px;line-height:1.6;color:var(--muted);padding:6px 22px 16px;min-height:52px}
.block-note b{color:var(--fg);font-weight:600}

.ctrl-group h2{margin-bottom:6px}
.field-row{margin-top:12px}
.field-row label{margin-bottom:6px;color:var(--fg);font-size:12px}
.param{margin-top:10px}
.param-head{display:flex;justify-content:space-between;align-items:baseline;gap:10px}
.param-head label{color:var(--fg);font-size:12px}
.param-head output{font:13px var(--mono)}
.param input[type=range]{margin:0;display:block;height:36px;min-height:36px}
.add-row{margin-top:14px;display:grid;gap:8px}
.mini-label{font-size:12px;color:var(--fg)}
.seg{display:grid;grid-template-columns:1fr 1fr 1fr;gap:4px;padding:4px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}
.seg button{font-size:11px;padding:6px 4px;min-height:40px;background:transparent;border-color:transparent;display:flex;align-items:center;justify-content:center;gap:6px;white-space:nowrap}
.seg button[aria-checked=true]{background:var(--raised);border-color:var(--app-accent)}
button.ghost{background:transparent;font-size:12px}
.ctrl-note{font-size:11px;line-height:1.6;color:var(--muted);margin-top:12px}
.ctrl-note output{font:11px var(--mono)}

.insight{grid-area:insight;display:flex;gap:16px;align-items:flex-start;padding:18px 24px;border-top:1px solid var(--line);background:color-mix(in srgb,var(--bg) 30%,var(--panel))}
.insight-dot{width:10px;height:10px;border-radius:50%;background:var(--muted);margin-top:4px;flex:none;box-shadow:0 0 0 5px color-mix(in srgb,var(--muted) 18%,transparent)}
.insight[data-tone=good] .insight-dot{background:#5ad69a;box-shadow:0 0 0 5px #5ad69a2e}
.insight[data-tone=learn] .insight-dot{background:var(--app-accent);box-shadow:0 0 0 5px #ff8a1f2e}
.insight[data-tone=warn] .insight-dot{background:var(--danger);box-shadow:0 0 0 5px color-mix(in srgb,var(--danger) 22%,transparent)}
.insight .eyebrow{margin-bottom:4px}
.insight h3{font:600 17px/1.3 var(--font);letter-spacing:-.02em;margin-bottom:3px}
.insight p:not(.eyebrow){font-size:13px;color:var(--muted);max-width:900px}

/* Challenges and learning cards */
.challenges{margin-top:28px}
.section-head{display:flex;justify-content:space-between;align-items:flex-end;gap:16px;margin-bottom:14px}
.section-head h2,.card h2{font:600 22px/1.2 var(--font);letter-spacing:-.035em}
.score{font:12px var(--mono);color:var(--muted)}
.challenge-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
.challenge{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:20px;display:flex;flex-direction:column;gap:10px;min-width:0}
.challenge.done{border-color:color-mix(in srgb,#5ad69a 60%,var(--line))}
.challenge-top{display:flex;justify-content:space-between;align-items:center;gap:10px}
.challenge-top span{font:9px var(--mono);color:var(--accent-text);letter-spacing:.08em}
.badge-state{font:10px var(--mono);padding:4px 9px;border-radius:30px;border:1px solid var(--line);color:var(--muted);white-space:nowrap}
.challenge.done .badge-state{color:#5ad69a;border-color:#5ad69a80}
:root[data-theme=light] .challenge.done .badge-state{color:#1c7a4c}
.challenge h3{font:600 17px/1.3 var(--font);letter-spacing:-.02em}
.challenge p{font-size:13px;line-height:1.65;color:var(--muted)}
.challenge .check{font:11px var(--mono);color:var(--fg);opacity:.85}
.challenge button{margin-top:auto;align-self:flex-start;font-size:12px}

.learning-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:18px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:23px;min-width:0}
.card h2{margin-bottom:12px}
.card p:not(.eyebrow),.card li{font-size:13px;line-height:1.7;color:var(--muted)}
.formula{font:14px/2 var(--mono)!important;color:var(--accent-text)!important;margin-bottom:12px}
details{margin-top:16px;border-top:1px solid var(--line)}
summary{padding-block:14px;cursor:pointer;min-height:44px;font-size:13px;font-weight:600;color:var(--fg)}
details p{margin-bottom:10px}
.steps{padding-left:20px;margin:0 0 12px}
.steps li{margin-bottom:6px}
.steps strong{color:var(--fg)}
.plain{padding-left:18px;margin:0 0 12px}
.plain li{margin-bottom:5px}
.sources a,.related a{color:var(--fg)}
.related{margin-top:14px;font-size:12px!important}
.noscript{padding:20px;color:var(--muted)}
.app-footer{font-size:11px;margin-top:28px}

/* Responsive */
@media(max-width:1280px){.work-area{grid-template-columns:250px minmax(0,1fr) 300px}.presets{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:1100px){
  .work-area{grid-template-columns:minmax(0,1fr) 320px;grid-template-areas:"stage side" "insight insight" "controls controls"}
  .controls{border-right:0;border-top:1px solid var(--line);grid-template-columns:1fr 1fr;gap:28px}
  .intro-note{max-width:360px}
}
@media(max-width:860px){
  .work-area{grid-template-columns:minmax(0,1fr);grid-template-areas:"stage" "insight" "side" "controls"}
  .side{border-left:0;border-top:1px solid var(--line)}.insight{border-bottom:0}
  .field-wrap{max-width:560px}
  .challenge-grid,.learning-grid{grid-template-columns:minmax(0,1fr)}
  .meter-strip{grid-template-columns:repeat(2,minmax(0,1fr))}
  .meter-strip>div:nth-child(2){border-right:0}
  .meter-strip>div:nth-child(-n+2){border-bottom:1px solid var(--line)}
  .intro{flex-direction:column;align-items:flex-start;gap:16px;padding-bottom:24px}
  .intro-glyph{width:64px;height:64px}
  .view-toggles{margin-right:0}
}
@media(max-width:760px){.app-main{padding:26px 16px}.app-header{padding-inline:16px}}
@media(max-width:600px){
  .app-main{padding:22px 12px}
  .app-header strong{font-size:10px;letter-spacing:.06em}.app-header strong span{display:none}.app-header>a{font-size:11px}
  .intro h1{font-size:clamp(30px,8.6vw,40px)}
  .intro-note{gap:14px}.intro-glyph{display:none}.intro-note p{font-size:13px}
  .presets{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
  .presets button{padding:12px}
  .presets strong{font-size:14px}
  .bench-toolbar{padding:10px 12px;gap:8px}
  .tabs{flex:1}.tabs button{flex:1;padding-inline:8px}
  .view-toggles{order:3;width:100%;justify-content:space-between}
  .bench-actions{order:2}
  .bench-actions button{padding-inline:11px}
  .meter-strip>div{padding:11px 13px}
  .meter-strip strong{font-size:20px}
  .meter-strip small{font-size:10px}
  .stage-head,.block-head{padding:14px 14px 10px;flex-direction:column;gap:8px}
  .legend{justify-content:flex-start}
  .field-wrap{margin:0 12px;width:calc(100% - 24px)}
  .probe-line{padding-inline:12px;font-size:11px}
  .transport{padding:12px}
  .transport-buttons{flex:1}
  #play{flex:1}
  .speed{width:100%;justify-content:space-between}
  .speed select{flex:1;max-width:220px}
  #network{height:300px}
  .block-note{padding:6px 14px 14px}
  .controls{grid-template-columns:minmax(0,1fr);padding:16px 14px}
  .insight{padding:16px 14px;gap:12px}
  .challenge,.card{padding:18px}
  .section-head{flex-direction:column;align-items:flex-start;gap:4px}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important;animation:none!important}}

/* ---------- relayout (2026-10): field, settings and train button on one screen ---------- */
.bench{overflow:clip}
.field-dock{display:flex;justify-content:center;min-width:0}
@media(min-width:1100px){
  .bench-toolbar{padding:6px 16px}
  .meter-strip>div{padding:9px 20px 10px}.meter-strip strong{font-size:21px;margin:2px 0 0}
  .stage-head,.block-head{padding:12px 18px 8px}
  .stage-head h2,.block-head h2,.ctrl-group h2{font-size:17px}
  .field-wrap{max-width:min(560px,calc(100vh - 445px));min-width:300px}
  .probe-line{padding:6px 18px 2px;min-height:30px}
  .transport{padding:9px 16px}
  .controls{padding:14px 16px;gap:14px}
  .ctrl-group h2{margin-bottom:2px}
  .field-row{margin-top:8px}.field-row label{margin-bottom:4px}.field-row select{min-height:38px;font-size:14px;padding:6px 10px}
  .param{margin-top:6px}.param input[type=range]{height:28px;min-height:28px}
  .add-row{margin-top:8px;gap:6px}.seg button{min-height:34px}
  button.ghost{min-height:36px;padding-block:5px}
  .ctrl-note{margin-top:6px;line-height:1.5}
  #network{height:clamp(220px,calc(100vh - 640px),330px)}
  #loss{height:clamp(130px,calc(100vh - 760px),190px)}
  .block-note{padding:4px 18px 10px;min-height:0}
}
@media(min-width:1100px) and (max-height:1050px){
  .intro{padding-bottom:22px}
  .presets{gap:8px;margin-bottom:14px}.presets button{padding:10px 13px 11px}.presets span{margin-bottom:5px}
  .presets strong{font-size:13.5px}.presets small{display:none}
}
/* phones: the field stays pinned at the top while the settings scroll under it */
@media(max-width:860px){
  .work-area{display:flex;flex-direction:column}
  .stage{display:contents}
  .field-dock{position:sticky;top:0;z-index:5;background:var(--panel);padding:8px 0;border-bottom:1px solid var(--line);box-shadow:0 8px 14px -8px #0005}
  .field-dock .field-wrap{margin:0;width:min(calc(100% - 24px),34vh)}
  .transport{margin-top:0}
  .controls{order:1;border-top:1px solid var(--line)}
  .insight{order:2}
  .side{order:3}
}