/* Alterna's shared panels and semantic tokens are inherited, not redefined per chapter. */
:root{color-scheme:dark;--reading:790px}
[data-theme="alakazam"],[data-theme="porygon-z"]{color-scheme:light}
html{scroll-padding-top:24px}
body{font-size:16px;overflow-wrap:break-word;padding-bottom:0}
button,input,select,textarea{font:inherit}
button,select{min-height:44px;border:1px solid var(--line);border-radius:9px;background:var(--panel2);color:var(--ink);padding:10px 14px}
button{cursor:pointer;font-size:14px;font-weight:650}
button:hover:not(:disabled){border-color:var(--cyan)}
button:disabled{opacity:.45;cursor:not-allowed}
button.primary,.button.primary{background:var(--cyan);border-color:var(--cyan);color:var(--accent-ink)}
:focus-visible{outline:3px solid var(--amber)!important;outline-offset:4px}
[hidden]{display:none!important}
[data-plot-controls],[data-slope-input]{cursor:grab;touch-action:none;}
.slice-comparison{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;}
.lesson-opening{max-width:80ch;margin:24px 0;line-height:1.8;}
.lesson-question-line{font-size:clamp(21px,3vw,30px);font-weight:800;}
.lesson-small-example{border-left:3px solid var(--amber);padding:4px 18px;margin:20px 0;}
.example-origin{font-size:13px;color:var(--muted);}
.experiment-mission{padding:14px 0;max-width:80ch;line-height:1.8;}
.lesson-discussion,.lesson-connection,.lesson-conclusion,.lesson-code{margin:32px 0;max-width:90ch;line-height:1.8;}
.lesson-code pre,.lesson-code-example pre{max-width:100%;min-width:0;overflow:auto;padding:18px;background:var(--panel);border:1px solid var(--line);border-radius:9px;font:13px/1.8 monospace;}
.lesson-code,.lesson-code-example{min-width:0;}
.svd-route{counter-reset:none;line-height:2;padding-left:30px;border-left:3px solid var(--cyan);}
.entropy-outcomes,.candidate-bars,.dot-contributions{display:grid;gap:14px;margin:18px 0;}
.token-order,.ffn-route,.embedding-lookup{display:flex;gap:15px;align-items:center;flex-wrap:wrap;padding:20px 0;grid-column:1/-1;}
.token-order span,.ffn-route span,.embedding-lookup span{padding:14px 18px;border:1px solid var(--line);border-radius:7px;background:var(--bg2);}
.token-order small{display:block;color:var(--muted);margin-top:5px;}
.head-comparison{display:grid;gap:20px;grid-column:1/-1;}
.score-bars,.embedding-neighbours{display:grid;gap:15px;width:100%;}
.experiment-ribbon,.request-slots,.expert-routing,.pipeline-tick,.token-progress,.sft-objective{display:flex;gap:12px;align-items:center;flex-wrap:wrap;grid-column:1/-1;}
.experiment-ribbon span,.request-slots span,.expert-routing span,.token-progress span,.sft-objective span{padding:13px;border:1px solid var(--line);border-radius:7px;background:var(--bg2);}
.experiment-ribbon [aria-current],.token-progress [aria-current],.shifted-pairs [aria-current]{border-color:var(--amber);font-weight:700;}
.shifted-pairs{display:grid;gap:12px;grid-column:1/-1;}.shifted-pairs>div{display:flex;gap:20px;border-left:3px solid var(--cyan);padding:15px;background:var(--bg2);}
.document-chunk,.ranked-documents,.context-budget,.memory-records,.agent-decisions,.worker-shards,.tensor-shards,.experiment-bars{grid-column:1/-1;max-width:100%;line-height:1.8;}
.ranked-documents li{margin:12px 0;padding:12px 16px;border-left:3px solid var(--cyan);}.foundation-output blockquote{margin:15px 0;padding:14px;border-left:3px solid var(--amber);background:var(--bg2);}
.worker-shards,.tensor-shards{display:flex;gap:18px;flex-wrap:wrap;}.worker-shards>section,.tensor-shards>section{flex:1 1 180px;min-width:0;}
.experiment-bars .bar-track{margin-bottom:18px;}
.scheduler-comparison,.memory-components{grid-column:1/-1;display:grid;gap:10px;}

/* Scientific reader, not a dashboard. */
.reader-context,.reader-opening,.reader-ending,.reader-code{max-width:78ch;margin:24px auto;line-height:1.85;}
.railwrap{background:none;border:0;padding:0;}.rail{gap:12px;padding:0 0 10px;}.rail a{background:none!important;border:0!important;border-bottom:1px solid var(--line)!important;border-radius:0;min-width:125px;min-height:0;padding:8px 10px;box-shadow:none;}.rail a.cur{border-bottom:2px solid var(--cyan)!important;}.rail .rt{font-size:12px;line-height:1.6;}.rail .rn{font-size:12px;}
.reader-context{font-size:14px;color:var(--muted);margin-bottom:12px;}.reader-question{font-weight:750;font-size:clamp(21px,3vw,28px);}.reader-example{padding-left:15px;border-left:2px solid var(--amber);}
.reader-model{max-width:1000px;margin:32px auto;padding:0;border:0!important;background:none!important;}.reader-model-label{font-size:20px;font-weight:650;margin-bottom:18px;}
.static-system>div{display:flex;gap:16px;align-items:center;flex-wrap:wrap;margin:20px 0;}.static-system span{padding:12px 15px;border-bottom:2px solid var(--cyan);}.static-system>div+div span{border-color:var(--line);color:var(--muted);font-size:14px;}.static-system figcaption{font-size:14px;line-height:1.8;color:var(--muted);}
.lesson-hero{grid-template-columns:1fr;min-height:0;padding-bottom:22px;}.lesson-hero h1{font-size:clamp(28px,4vw,45px);}
.reader-integration{padding:0;border:0;}.reader-integration .mg-frame-heading p{font-size:13px;color:var(--muted);}.reader-integration .mg-controls{margin:10px 0;}.reader-integration .mg-training,.reader-integration .mg-inference,.reader-integration .mg-assembly{border:0;padding:0;margin:12px 0;}.reader-integration h3{font-size:18px;}.reader-integration .mg-table{max-width:100%;border:0;}.reader-integration .mg-tensor-label{font-size:14px;}.reader-integration .mg-actions:empty,.reader-integration .mg-controls:empty{display:none;}
.compact-model{border:0!important;border-radius:0!important;box-shadow:none!important;background:none!important;overflow:hidden;}
.compact-caption{font-size:14px;color:var(--muted);margin:0;}.compact-model .lab-heading{padding:0 0 12px;background:none;}.compact-model .lab-controls{padding:0;background:none;border:0;grid-template-columns:repeat(3,minmax(0,1fr));}.compact-model .foundation-output{padding:18px 0;gap:20px;}.compact-model .lab-actions{padding:8px 0;}.compact-model .foundation-status{margin:8px 0;font-size:13px;}.compact-model .lab-controls textarea{min-height:80px;max-height:160px;resize:vertical;}
.reader-theory{margin:30px auto;}.reader-theory h3{padding-top:18px;border:0;}.reader-theory p{margin:14px 0;line-height:1.9;}.reader-code pre{white-space:pre;overflow:auto;background:var(--bg2);padding:16px;border:0;border-radius:6px;font:13px/1.8 monospace;}
.reader-next{font-weight:600;color:var(--cyan);margin-top:22px;}.reader-ending{border-top:1px solid var(--line);padding-top:18px;}
.reader-home-chain{display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin:15px 0 40px;}.reader-home-chain span{font-weight:650;}.reader-home-chain b{color:var(--muted);}.reader-chapters{max-width:950px;}.reader-chapter{padding:18px 0;border-bottom:1px solid var(--line);}.reader-chapter>a{display:flex;gap:20px;align-items:baseline;}.reader-chapter h3{margin:0;font-size:21px;}.reader-chapter>a>span{color:var(--muted);font:16px monospace;}.reader-chapter p{margin:8px 0 8px 44px;max-width:75ch;line-height:1.7;}.reader-handoff{font-size:14px;color:var(--muted);}.reader-hero{min-height:0;grid-template-columns:1fr;padding-bottom:28px;}.reader-hero h1{font-size:clamp(34px,6vw,68px);}
.geometry-figure{margin:0;}.geometry-figure canvas{display:block;width:100%;height:330px;max-height:440px;background:var(--bg2);border-radius:8px;}.geometry-figure figcaption{font-size:13px;color:var(--muted);line-height:1.7;margin:10px 0;}.geometry-controls{display:flex;gap:18px;flex-wrap:wrap;margin:18px 0;}.geometry-controls label{display:grid;flex:1 1 170px;gap:7px;font-size:14px;}.geometry-controls input{min-height:44px;width:100%;}.geometry-controls output{font-family:monospace;}.geometry-readout{line-height:1.8;max-width:80ch;}
@media(max-width:600px){.compact-model .lab-controls{grid-template-columns:1fr;}.reader-chapter p{margin-left:0;}.reader-theory,.reader-opening,.reader-ending,.reader-code{max-width:100%;}.geometry-figure canvas{height:260px;}.reader-home-chain{gap:8px;}}
.teacher-weights-guide{margin:24px 0;padding-left:18px;border-left:3px solid var(--amber);max-width:80ch;line-height:1.8;}
@media(max-width:600px){.slice-comparison{grid-template-columns:1fr;}}
input[type=text],input[type=number],input[type=search],select{font-size:16px;min-height:44px;width:100%;min-width:0}
input[type=search]{background:var(--bg2);border:1px solid var(--line);border-radius:8px;color:var(--ink);padding:10px 12px}
input[type=checkbox],input[type=radio]{width:20px;height:20px;flex-shrink:0;accent-color:var(--cyan)}
.sitebar{max-width:1240px;margin:0 auto;padding:22px 28px;display:flex;align-items:center;gap:24px;border-bottom:1px solid var(--line)}
.brand{color:var(--ink);font-size:21px;font-weight:800;letter-spacing:-.8px;white-space:nowrap;display:flex;gap:9px;align-items:center}
.brand svg{width:30px;height:30px}
.brand span{color:var(--cyan);font-weight:500}
.sitebar nav{display:flex;gap:20px;flex:1;font-size:13px}
.sitebar nav a{color:var(--muted);padding:12px 0}
.sitebar button{font-size:12px}
.wrap{max-width:1240px;padding:0 28px}
.eyebrow{font:11px/1.6 "JetBrains Mono",monospace;letter-spacing:.12em;color:var(--cyan);text-transform:uppercase}
.hero{background:none;text-align:left;border:0;max-width:1240px;margin:0 auto;padding:58px 28px 24px;display:grid;grid-template-columns:1fr 270px;gap:40px}
.hero h1{font-size:clamp(34px,5vw,64px);line-height:1.09;letter-spacing:-2.4px;max-width:890px;margin:20px 0 22px;font-weight:800}
.hero>div{min-width:0}
.hero h1{overflow-wrap:anywhere}
.hero h1 em{font-style:normal;color:var(--cyan)}
.hero p{font-size:17px;max-width:760px;margin:0;line-height:1.75;color:var(--muted)}
.hero .hero-aside{border-left:1px solid var(--line);align-self:end;padding-left:26px}
.hero-aside .index-number{font:64px/1 monospace;color:var(--line);letter-spacing:-4px}
.hero-aside p{font-size:13px;margin:16px 0}
.hero.lesson-hero{padding-top:34px;padding-bottom:12px;grid-template-columns:minmax(0,1fr) 230px;gap:28px}
.hero.lesson-hero h1{font-size:clamp(30px,4vw,46px);line-height:1.12;margin:12px 0 12px;letter-spacing:-1.6px}
.hero.lesson-hero p{font-size:15px;line-height:1.65}
.hero.lesson-hero .hero-aside{align-self:center}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}
.button{display:inline-flex;align-items:center;justify-content:center;min-height:46px;border:1px solid var(--line);border-radius:9px;padding:12px 18px;font-size:14px;font-weight:700;color:var(--ink);background:var(--panel)}
.button:hover{text-decoration:none;border-color:var(--cyan)}
.release-note{font:12px/1.6 monospace;color:var(--muted);margin:12px 0 0}
.progress-panel{display:flex;gap:16px;align-items:center;flex-wrap:wrap;border-block:1px solid var(--line);padding:12px 4px;margin:18px 0 24px}
.progress-panel p{margin:0;font-size:13px;flex:1;min-width:180px}
progress{accent-color:var(--cyan);width:160px;height:8px}
.lab-shell{background:var(--panel);border:1px solid var(--line);border-radius:16px;margin:28px 0 40px;overflow:hidden;box-shadow:0 15px 60px #00000012;border-top:3px solid var(--cyan)}
.lab-heading{padding:26px 28px 8px}
.lab-heading h2{font-size:25px;letter-spacing:-.7px;margin:8px 0}
.lab-heading p{font-size:14px;color:var(--muted);max-width:900px}
.lab-disclaimer{border-left:2px solid var(--amber);padding-left:12px;line-height:1.65}
.lab-controls{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:16px;padding:16px 28px 24px}
.lab-controls label{font-size:12px;line-height:1.6;color:var(--muted)}
.lab-controls input,.lab-controls select{margin-top:6px}
.lab-controls .wide{grid-column:span 2}
.lab-controls .toggle{display:flex;align-items:center;gap:10px;min-height:44px;font-size:13px}
.lab-controls .toggle input{margin:0;width:20px}
.step-nav{display:flex;overflow-x:auto;gap:0;background:var(--bg2);padding:0 20px;border-block:1px solid var(--line)}
.step-nav button{flex:0 0 122px;border:0;border-bottom:2px solid transparent;border-radius:0;background:none;text-align:left;font-size:11px;line-height:1.4;padding:13px 12px;min-height:66px;color:var(--muted)}
.step-nav button span{display:block;font:11px monospace;margin-bottom:4px}
.step-nav button.active{color:var(--cyan);border-bottom-color:var(--cyan);background:var(--panel)}
.lab-workspace{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(0,1fr);min-height:265px}
.stage-view{padding:26px 28px;min-width:0;display:flex;flex-direction:column;justify-content:center}
.stage-view .tblbox{margin:0}
.stage-note{border-left:1px solid var(--line);padding:26px;background:var(--bg2);min-width:0}
.stage-note h3{margin:9px 0 15px;font-size:20px}
.stage-note .note{font-size:14px;color:var(--muted);line-height:1.8}
.formula-line{font:14px/1.8 "JetBrains Mono",monospace;color:var(--amber);overflow-wrap:anywhere}
.stage-count{font:11px monospace;color:var(--muted);margin-top:22px;line-height:1.6}
.lab-actions{display:flex;gap:10px;flex-wrap:wrap;padding:20px 28px;border-top:1px solid var(--line)}
.lab-actions button:last-child{margin-left:auto}
.inspector{border-top:1px solid var(--line);padding:0 28px}
summary{cursor:pointer;min-height:44px;padding:16px 0;font-size:14px;font-weight:650}
.inspector p{font-size:12px;color:var(--muted)}
.inspector pre,.state-preview{background:var(--bg2);padding:16px;border:1px solid var(--line);border-radius:8px;font:12px/1.6 monospace;overflow:auto;max-height:420px;white-space:pre;max-width:100%;margin:0 0 20px}
.privacy-line{font:11px/1.8 monospace;padding:0 28px 16px;color:var(--muted)}
.lab-error{margin:0 28px 20px;border:1px solid var(--red);padding:12px;color:var(--red);border-radius:8px}
.token-row{display:flex;gap:10px;flex-wrap:wrap}
.token{padding:14px 17px;border:1px solid var(--cyan);border-radius:8px;background:var(--bg2);font:16px monospace}
.token small{display:block;font-size:10px;color:var(--muted);margin-top:9px}
.flow-strip,.system-flow{display:flex;gap:9px;align-items:center;flex-wrap:wrap}
.flow-strip span,.system-flow span{border:1px solid var(--line);padding:15px;border-radius:8px;background:var(--bg2);font-size:14px}
.flow-strip b{color:var(--cyan)}
.system-flow span:not(:last-child)::after{content:' →';color:var(--cyan)}
.matrix{font-family:monospace;white-space:nowrap}
.matrix caption{font:12px/1.7 monospace;text-align:left;color:var(--muted);padding-bottom:10px;white-space:normal}
.matrix td{font-size:12px!important}
.probabilities{display:grid;gap:8px}
.prob-row{display:grid;grid-template-columns:75px 1fr 64px;align-items:center;gap:12px;font:12px monospace}
.prob-row strong{text-align:right;font-weight:400;color:var(--amber)}
.bar-track{height:10px;background:var(--bg2);border-radius:2px;overflow:hidden}
.bar-track i{display:block;height:100%;background:var(--cyan);min-width:0}
.sample-result{text-align:center;display:grid;gap:15px}
.sample-result span,.sample-result small{font:12px/1.7 monospace;color:var(--muted)}
.sample-result strong{font-size:46px;color:var(--cyan)}
.metric-pair{display:flex;gap:50px;justify-content:center}
.metric-pair span{display:block;color:var(--muted);font-size:12px}
.metric-pair strong,.large-number{font:48px monospace;color:var(--amber);margin:18px 0}
.template-result{font-size:19px;line-height:1.8;white-space:pre-line}
.function-plot{display:block;width:calc(100% - 56px);margin:0 28px;color:var(--muted);background:var(--bg2);border-radius:9px}
.function-plot text{fill:currentColor;font:12px monospace}
.loss-plot{display:block;width:100%;color:var(--muted);margin-top:10px}
.loss-plot text{fill:currentColor;font:13px monospace}
[data-lab=model]>.formula-line,[data-lab=model]>button{margin:20px 28px}
.section-title{display:flex;justify-content:space-between;align-items:baseline;gap:20px;margin:54px 0 16px;border-top:1px solid var(--line);padding-top:24px}
.section-title h2{font-size:28px;letter-spacing:-.8px;margin:0}
.section-title span{font:11px monospace;color:var(--cyan)}
.route-controls{display:flex;gap:8px;flex-wrap:wrap;margin:20px 0}
.route-controls button[aria-pressed=true]{background:var(--cyan);color:var(--accent-ink)}
.search-label{display:block;max-width:480px;font-size:13px;color:var(--muted)}
.search-label input{margin-top:8px}
.map-status{font-size:13px;color:var(--muted);line-height:1.7;max-width:850px}
.dependency-graph{width:100%;height:auto;display:block;background:var(--bg2);border-radius:12px;margin:24px 0;border:1px solid var(--line)}
.dependency-graph line{stroke:var(--line);stroke-width:2}
.dependency-graph line.related{stroke:var(--cyan);stroke-width:3}
.dependency-graph line.dimmed{opacity:.12}
.dependency-graph circle{fill:var(--panel2);stroke:var(--muted)}
.dependency-graph a:first-of-type circle{stroke:var(--cyan);fill:var(--panel)}
.dependency-graph text{fill:var(--ink);font:15px monospace;text-anchor:middle;dominant-baseline:central}
.dependency-graph a:hover circle,.dependency-graph a:focus circle{stroke:var(--cyan);stroke-width:3}
.course-groups{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.course-group{min-width:0;border-top:2px solid var(--line);padding-top:12px}
.group-title{font:12px monospace;color:var(--cyan);display:flex;gap:12px;margin:0 0 14px}
.chapter-node{border-bottom:1px solid var(--line);padding:10px 4px;scroll-margin-top:30px}
.chapter-node summary{display:flex;align-items:center;gap:13px;line-height:1.5;padding:6px 0}
.chapter-number{font:13px monospace;color:var(--muted);min-width:24px}
.chapter-node summary .planned{margin-left:auto;font:10px/1.5 monospace;white-space:nowrap;color:var(--muted)}
.chapter-node summary::after{content:'+';font:16px monospace;color:var(--cyan)}
.chapter-node[open] summary::after{content:'−'}
.chapter-node p{font-size:14px;color:var(--muted);line-height:1.7}
.chapter-node .available{color:var(--green)}
.chapter-node .prerequisites{font-size:12px}
.railwrap{max-width:1240px;padding:0 28px}
.rail a{min-width:0;flex-basis:135px;min-height:58px}
.lesson-question{max-width:930px;margin:34px auto 18px;padding:28px 32px;border-left:4px solid var(--cyan);background:linear-gradient(90deg,color-mix(in srgb,var(--cyan) 8%,var(--panel)),transparent);border-radius:0 14px 14px 0}
.lesson-question h2{font-size:clamp(24px,3.4vw,38px);line-height:1.25;letter-spacing:-1px;margin:8px 0 10px}
.lesson-question p{max-width:760px;color:var(--muted);line-height:1.75;margin:0}
.stage-kicker{font:11px/1.6 "JetBrains Mono",monospace;letter-spacing:.11em;color:var(--cyan)}
.lesson-path{max-width:930px;margin:0 auto 34px;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--panel)}
.lesson-path a{min-width:0;padding:14px 16px;color:var(--muted);font-size:13px;font-weight:700;border-right:1px solid var(--line);display:flex;align-items:center;gap:9px}
.lesson-path a:last-child{border-right:0}
.lesson-path a span{font:11px monospace;color:var(--cyan)}
.lesson-path a:hover,.lesson-path a.active{background:color-mix(in srgb,var(--cyan) 9%,var(--panel));color:var(--ink);text-decoration:none}
.lesson-stage{scroll-margin-top:20px;margin:0 0 64px}
.stage-heading{max-width:1080px;margin:0 auto 10px;display:flex;align-items:center;gap:15px;border-bottom:1px solid var(--line);padding:0 0 13px}
.stage-heading>span{font:28px/1 "JetBrains Mono",monospace;color:color-mix(in srgb,var(--cyan) 70%,var(--muted))}
.stage-heading p{font-size:18px;font-weight:800;margin:0 0 2px}
.stage-heading small{font-size:13px;color:var(--muted)}
.stage-observe{max-width:1160px;margin-left:auto;margin-right:auto}
.stage-check{max-width:880px;margin-left:auto;margin-right:auto}
.stage-experiment{max-width:1160px;margin-left:auto;margin-right:auto}
.code-reveal,.boundary-note{border:1px solid var(--line);border-radius:10px;margin:24px 0;background:var(--panel)}
.code-reveal summary,.boundary-note summary{padding:15px 18px;color:var(--muted)}
.code-reveal[open] summary,.boundary-note[open] summary{color:var(--cyan);border-bottom:1px solid var(--line)}
.code-reveal pre{margin:0!important;border:0!important;border-radius:0 0 10px 10px!important}
.boundary-note p{padding:0 18px 18px;margin:0!important;color:var(--muted)}
.interpretation-note{border-left:3px solid var(--amber);padding:14px 18px;background:color-mix(in srgb,var(--amber) 5%,transparent);border-radius:0 8px 8px 0}
.lesson-body{max-width:var(--reading);margin:42px auto;font-size:16px;line-height:1.9}
.lesson-body h3{font-size:24px;letter-spacing:-.5px;line-height:1.4;margin:42px 0 15px}
.lesson-body h4{font-size:18px;margin:30px 0 12px}
.lesson-body p{margin:16px 0}
.lesson-body strong{font-weight:750}
.lesson-body blockquote{border-left:3px solid var(--cyan);margin:24px 0;padding:4px 24px;background:var(--panel)}
.lesson-body pre{overflow:auto;padding:20px;background:var(--panel);border:1px solid var(--line);border-radius:9px;font:13px/1.8 monospace}
.lesson-body pre code{background:none;padding:0;color:var(--ink);font-size:inherit}
.lesson-body table{border-collapse:collapse;width:100%;font-size:13px;line-height:1.7}
.lesson-body th,.lesson-body td{padding:12px;border-bottom:1px solid var(--line);text-align:left}
.lesson-body th{background:var(--panel);color:var(--cyan)}
.lesson-body .math-block{overflow-x:auto;padding:16px 4px}
.lesson-body .katex-display{margin:0}
.lesson-body .katex{font-size:1.05em}
.lesson-body-continuation{margin-top:34px}
.concept-visual{max-width:1080px;margin:42px auto;border:1px solid var(--line);border-top:3px solid var(--amber);border-radius:16px;background:linear-gradient(145deg,var(--panel),var(--bg2));overflow:hidden;box-shadow:0 20px 70px #00000016}
.concept-visual>header{padding:26px 28px 18px;border-bottom:1px solid var(--line)}
.concept-visual>header h2{font-size:clamp(24px,4vw,34px);letter-spacing:-1px;margin:7px 0 8px}
.concept-visual>header p{max-width:780px;color:var(--muted);line-height:1.7;margin:0}
.visual-task{display:flex;gap:18px;align-items:flex-start;padding:15px 28px;background:color-mix(in srgb,var(--amber) 7%,var(--bg2));border-bottom:1px solid var(--line)}
.visual-task span,.visual-canvas-toolbar>span,.concept-visual-copy>div>span{font:10px/1.6 "JetBrains Mono",monospace;letter-spacing:.1em;color:var(--amber);text-transform:uppercase;white-space:nowrap}
.visual-task p{font-size:13px;line-height:1.7;margin:0;color:var(--muted)}
.visual-steps{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));background:var(--bg2);border-bottom:1px solid var(--line);overflow-x:auto}
.visual-steps button{min-height:70px;border:0;border-right:1px solid var(--line);border-radius:0;background:transparent;color:var(--muted);font-size:11px;line-height:1.35;text-align:left;padding:12px}
.visual-steps button:last-child{border-right:0}
.visual-steps button span{display:block;font:10px monospace;color:var(--muted);margin-bottom:6px}
.visual-steps button[aria-pressed="true"]{background:var(--panel);color:var(--ink);box-shadow:inset 0 -3px var(--amber)}
.visual-steps button.visited span,.visual-steps button[aria-pressed="true"] span{color:var(--cyan)}
.visual-canvas-toolbar{display:flex;align-items:center;justify-content:space-between;padding:8px 14px 8px 28px;border-bottom:1px solid var(--line)}
.visual-canvas-toolbar>div{display:flex;gap:6px}
.visual-canvas-toolbar button{min-height:34px;padding:6px 10px;font-size:11px}
.visual-canvas-toolbar button[aria-pressed="true"]{border-color:var(--cyan);color:var(--cyan);background:color-mix(in srgb,var(--cyan) 8%,var(--panel2))}
.concept-visual-canvas{overflow:hidden;background:radial-gradient(circle at 50% 10%,color-mix(in srgb,var(--cyan) 8%,transparent),transparent 48%);scrollbar-width:thin}
.concept-visual-canvas svg{display:block;width:100%;min-width:700px;height:auto;color:var(--muted)}
.concept-visual-canvas svg text{font-family:"JetBrains Mono",monospace;fill:var(--muted)}
.concept-visual-canvas svg .svg-title{font-family:Manrope,sans-serif;font-size:18px;font-weight:800;fill:var(--ink)}
.concept-visual-canvas svg .svg-label{font-size:13px;fill:var(--ink)}
.concept-visual-canvas svg .svg-small{font-size:11px}
.concept-visual-canvas svg .svg-node{fill:var(--panel);stroke:var(--line);stroke-width:1.5}
.concept-visual-canvas svg .svg-node.active{stroke:var(--cyan);stroke-width:3;filter:drop-shadow(0 0 7px color-mix(in srgb,var(--cyan) 35%,transparent))}
.concept-visual-canvas svg .svg-node.target{stroke:var(--amber);stroke-width:3}
.concept-visual-canvas svg .svg-flow{fill:none;stroke:var(--line);stroke-width:3;stroke-linecap:round}
.concept-visual-canvas svg .svg-flow.active{stroke:var(--cyan);stroke-dasharray:10 8;animation:svg-flow 1.1s linear infinite}
.concept-visual-canvas svg .svg-grid{fill:none;stroke:var(--line);stroke-width:1;opacity:.42}
.concept-visual-canvas svg .svg-axis{fill:none;stroke:var(--muted);stroke-width:1.5}
.concept-visual-canvas svg .svg-tick{font-size:9px;fill:var(--muted)}
.concept-visual-canvas svg .svg-vector{fill:none;stroke-width:4;stroke-linecap:round}
.concept-visual-canvas svg .svg-vector.svg-muted{stroke-dasharray:7 7;opacity:.55}
.concept-visual-canvas svg .svg-helper{fill:none;stroke:var(--muted);stroke-width:2;stroke-dasharray:6 7}
.concept-visual-canvas svg .svg-unit-ball{fill:color-mix(in srgb,var(--cyan) 10%,transparent);stroke:var(--cyan);stroke-width:4}
.concept-visual-canvas svg .svg-enter{transform-box:fill-box;transform-origin:center;animation:svg-enter .48s ease-out both}
.concept-visual-canvas svg .svg-draw{stroke-dasharray:1200;stroke-dashoffset:1200;animation:svg-draw .9s ease-out forwards}
.concept-visual-canvas svg .svg-bar{transform-box:fill-box;transform-origin:center bottom;animation:svg-bar .55s ease-out both}
.concept-visual-copy{display:grid;grid-template-columns:minmax(220px,.8fr) minmax(0,1.5fr);gap:0;border-top:1px solid var(--line)}
.concept-visual-copy>div{padding:18px 28px}
.concept-visual-copy>div+div{border-left:1px solid var(--line)}
.concept-visual-copy>div>span{color:var(--cyan)}
.visual-formula{font:13px/1.8 "JetBrains Mono",monospace;color:var(--amber);margin:0}
.visual-caption{font-size:14px;line-height:1.8;margin:0;color:var(--muted)}
.concept-visual-controls{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:18px 28px;border-top:1px solid var(--line)}
.concept-visual-controls label{display:flex;align-items:center;gap:10px;flex:1;min-width:180px;font-size:12px;color:var(--muted)}
.concept-visual-controls input{min-height:24px;width:100%}
.concept-visual-controls [data-visual-status]{font:11px/1.5 monospace;color:var(--muted);min-width:92px;text-align:right}
.visual-auto{display:flex;align-items:center;border:1px solid var(--line);border-radius:9px;padding:0 8px}
.visual-auto summary{font-size:12px;min-height:42px;padding:11px 4px}
.visual-auto[open]{display:flex;gap:6px;align-items:center}
.visual-auto button{min-height:34px;padding:5px 9px}
@keyframes svg-flow{to{stroke-dashoffset:-36}}
@keyframes svg-enter{from{opacity:0;transform:scale(.94)}to{opacity:1;transform:scale(1)}}
@keyframes svg-draw{to{stroke-dashoffset:0}}
@keyframes svg-bar{from{opacity:.25;transform:scaleY(.05)}to{opacity:1;transform:scaleY(1)}}
.concept-check,.checkpoint,.sort-lab{border:1px solid var(--line);background:var(--panel);border-radius:12px;padding:26px;margin:28px auto;max-width:var(--reading)}
.concept-check{border-left:4px solid var(--amber);padding:30px 32px}
.concept-check h2{font-size:24px;margin:7px 0 18px}
fieldset{border:0;padding:0;margin:0;min-width:0}
legend{font-weight:700;font-size:17px;line-height:1.6;margin-bottom:14px;max-width:100%;overflow-wrap:anywhere;white-space:normal}
.answer-label{display:flex;align-items:center;gap:12px;min-height:48px;padding:12px;border:1px solid var(--line);border-radius:8px;margin:8px 0;background:var(--bg2);font-size:14px}
.concept-check button,.checkpoint>button,.sort-lab>button{margin-top:16px}
.feedback{line-height:1.7}
.checkpoint [data-task]{border-bottom:1px solid var(--line);padding-bottom:24px;margin-bottom:26px}
.checkpoint .numeric-label{display:block;font-size:14px}
.checkpoint .numeric-label input{margin-top:10px}
.checkpoint-result{max-width:var(--reading);padding:20px;margin:24px auto;background:var(--panel);border:1px solid var(--cyan);border-radius:9px;line-height:1.8}
.sort-row{border-bottom:1px solid var(--line);padding:12px 0}
.sort-row label{display:grid;grid-template-columns:1fr 1fr;align-items:center;gap:15px;font-size:14px}
.glossary{max-width:var(--reading);margin:40px auto}
.glossary dt{font-size:20px;font-weight:750;color:var(--cyan);padding-top:24px;border-top:1px solid var(--line)}
.glossary dd{margin:12px 0 24px;line-height:1.8;color:var(--muted)}
.footer{max-width:1240px;margin:64px auto 0;padding:28px;border-top:1px solid var(--line);display:flex;justify-content:space-between;flex-wrap:wrap;gap:18px;font-size:12px;color:var(--muted)}
.footer nav{display:flex;gap:22px}
.code-download{max-width:var(--reading);margin:25px auto}
.foundation-output{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:22px;padding:24px 28px;align-items:start}
.foundation-output>*{min-width:0}
.foundation-output>p,.foundation-output>.flow-strip{grid-column:1/-1;line-height:1.8;font-size:14px}
.foundation-output .tblbox{margin:0}
.foundation-output caption{font-size:13px;text-align:left;padding:10px 0;color:var(--muted)}
.foundation-output td{overflow-wrap:anywhere;font-family:monospace;font-size:13px}
.foundation-plot,.foundation-curve{display:block;width:100%;background:var(--bg2);border-radius:10px}
.foundation-plot text,.foundation-curve text{fill:var(--muted);font:16px monospace}
.foundation-status{margin:0 28px 20px;font-size:13px;color:var(--muted)}
.graph-editor{grid-column:1/-1}
.graph-editor textarea{font-size:16px;min-height:290px}
.graph-scroll{grid-column:1/-1;max-width:100%;overflow:auto;border:1px solid var(--line);border-radius:10px}
.autograd-graph{display:block;width:100%;max-height:none}
.autograd-graph text{fill:var(--ink);font:13px monospace}
.fp-fields{display:flex;gap:12px;flex-wrap:wrap;grid-column:1/-1}
.fp-fields span{padding:12px;border:1px solid var(--line);border-radius:9px;min-width:0;background:var(--bg2)}
.fp-fields b{display:block;font:16px monospace;color:var(--cyan);overflow-wrap:anywhere;margin-top:8px}
.heat-table td{text-align:center;min-width:40px;font-size:12px!important;white-space:nowrap}
.heat-table .active-window{outline:2px solid var(--amber);outline-offset:-2px}
[data-compute-lab] .lab-actions label{display:flex;align-items:center;gap:15px;flex:1;min-width:160px}
[data-compute-lab] input[type=range]{min-height:24px}
[data-compute-lab] .graph-editor textarea{min-height:100px;font-size:16px}
[data-language-lab] .graph-editor textarea{min-height:90px;font-size:16px}
[data-language-lab] .lab-actions label{display:flex;align-items:center;gap:15px;flex:1;min-width:160px}
[data-language-lab] input[type=range]{min-height:24px}
[data-final-lab] .graph-editor textarea{min-height:170px;font-size:16px}
[data-final-lab] .lab-actions label{display:flex;align-items:center;gap:15px;flex:1;min-width:160px}
[data-final-lab] input[type=range]{min-height:24px}
[data-final-lab] .state-preview{grid-column:1/-1;max-height:360px;overflow:auto;white-space:pre-wrap;overflow-wrap:anywhere}
.language-wide{grid-column:1/-1;max-width:100%;min-width:0}
.language-wide>.tblbox{max-height:420px;overflow:auto}
[data-neural-lab] .lab-actions label{display:flex;align-items:center;gap:15px;flex:1;min-width:160px}
[data-neural-lab] input[type=range]{min-height:24px}
.foundation-output .bar-track{margin-bottom:6px;height:13px}
[data-foundation-lab] .lab-actions label{display:flex;align-items:center;gap:15px;flex:1;min-width:160px}
[data-foundation-lab] input[type=range]{min-height:24px}
.experiment-method{margin-top:20px;padding:16px 18px;background:var(--bg2);border:1px solid var(--line);border-radius:10px}
.experiment-method ol{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;list-style:none;padding:0;margin:0 0 12px}
.experiment-method li{font-size:11px;color:var(--muted);display:flex;align-items:center;gap:8px}
.experiment-method li span{display:grid;place-items:center;width:24px;height:24px;border:1px solid var(--line);border-radius:50%;font:10px monospace}
.experiment-method li.active{color:var(--ink)}
.experiment-method li.active span{border-color:var(--cyan);color:var(--cyan);background:color-mix(in srgb,var(--cyan) 9%,var(--panel))}
.experiment-method p{font-size:13px;line-height:1.7;margin:0;color:var(--muted)}
.experiment-method p strong{color:var(--amber)}
.lab-controls>.primary-control{border-left:2px solid var(--cyan);padding-left:12px}
.lab-controls>.secondary-control{opacity:.82}
.advanced-controls{grid-column:1/-1;border:1px solid var(--line);border-radius:9px;padding:0 14px;background:var(--bg2)}
.advanced-controls summary{color:var(--muted);font-size:12px}
.advanced-controls>div{display:grid;grid-template-columns:repeat(auto-fit,minmax(160px,1fr));gap:16px;padding:4px 0 16px}
.advanced-controls>p{font-size:12px;color:var(--muted);margin:0 0 10px}
.final-config>div{display:block}
.final-config textarea{width:100%;margin-top:8px}
.lab-scenarios{display:flex;align-items:center;gap:9px;flex-wrap:wrap;padding:16px 28px;border-block:1px solid var(--line);background:var(--bg2)}
.lab-scenarios>span{font:10px/1.5 monospace;letter-spacing:.1em;color:var(--cyan);margin-right:6px;text-transform:uppercase}
.result-story{grid-column:1/-1;border-left:3px solid var(--cyan);padding:3px 0 3px 16px}
.result-story h3{font-size:21px;margin:5px 0}
.result-story p{font-size:13px;color:var(--muted);margin:0;line-height:1.7}
@media(max-width:760px){.foundation-output{grid-template-columns:minmax(0,1fr);padding:16px}.foundation-status{margin:0 16px 16px}.foundation-output>p{grid-column:auto}.concept-visual-copy{grid-template-columns:1fr}.concept-visual-copy>div+div{border-left:0;border-top:1px solid var(--line)}.concept-visual-canvas svg{min-width:0}.visual-steps{grid-template-columns:repeat(5,minmax(132px,1fr))}.experiment-method ol{grid-template-columns:1fr}.lesson-path{display:flex;overflow-x:auto}.lesson-path a{flex:0 0 55%;border-right:1px solid var(--line)}.lesson-question{padding:22px 20px}.lesson-stage{margin-bottom:48px}}
@media(max-width:900px){.hero,.hero.lesson-hero{grid-template-columns:1fr;padding-top:36px}.hero .hero-aside{display:none}.sitebar{gap:14px;flex-wrap:wrap}.sitebar nav{order:3;flex-basis:100%}.sitebar button{margin-left:auto}.lab-workspace{grid-template-columns:1fr}.stage-note{border-left:0;border-top:1px solid var(--line)}.course-groups{grid-template-columns:1fr}.hero h1{max-width:750px}.stage-view{min-height:200px}}
@media(max-width:520px){.sitebar,.wrap,.hero,.railwrap{padding-left:16px;padding-right:16px}.sitebar{padding-top:14px}.brand{font-size:19px}.sitebar button{max-width:148px;font-size:11px}.hero h1{letter-spacing:-1.5px;font-size:38px}.hero.lesson-hero{padding-top:24px}.hero.lesson-hero h1{font-size:31px}.hero p{font-size:15px}.hero-actions{flex-direction:column}.hero-actions a{width:100%}.lab-heading,.stage-view,.stage-note{padding:20px 16px}.lab-controls{padding:16px;grid-template-columns:1fr}.lab-controls .wide{grid-column:auto}.lab-actions{padding:16px;gap:8px}.lab-actions button{flex:1 1 80px}.lab-actions button:last-child{margin-left:0}.inspector{padding:0 16px}.privacy-line{padding:0 16px 16px}.step-nav{padding:0 8px}.prob-row{grid-template-columns:65px 1fr 58px;gap:7px;font-size:11px}.lab-error{margin:0 16px 16px}.concept-check,.checkpoint,.sort-lab{padding:18px}.concept-check{padding:22px 18px}.sort-row label{grid-template-columns:1fr}.lesson-body{font-size:15px;margin:30px auto}.lesson-body h3{font-size:22px}.section-title h2{font-size:24px}.chapter-node summary{font-size:14px;gap:8px}.chapter-node summary .planned{font-size:9px}.function-plot{width:calc(100% - 32px);margin:0 16px}.dependency-graph{display:none}.progress-panel{padding:12px 0}.progress-panel button{min-height:36px;padding:7px 9px}.rail{flex-wrap:nowrap;overflow-x:auto}.rail a{flex:0 0 68%}.footer{padding:24px 16px}.concept-visual>header,.concept-visual-copy>div,.concept-visual-controls,.visual-task{padding-left:16px;padding-right:16px}.concept-visual-controls button{flex:1 1 115px}.concept-visual-controls [data-visual-status]{width:100%;text-align:left}.visual-task{display:block}.visual-task span{display:block;margin-bottom:5px}.visual-canvas-toolbar{padding-left:16px}.visual-canvas-toolbar>span{display:none}.stage-heading{align-items:flex-start}.stage-heading>span{font-size:22px}.lab-scenarios{padding:14px 16px}.lab-scenarios button{flex:1 1 130px}.advanced-controls>div{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media print{.sitebar,.lab-shell,.progress-panel,.route-controls,.search-label,.concept-check,.checkpoint,.sort-lab,.concept-visual-controls{display:none}.callout{display:block!important}.hero{padding:10px 0}.hero h1{font-size:28px}.lesson-body{max-width:none}.footer{margin-top:20px}.lesson-body pre{white-space:pre-wrap}.tblbox{overflow:visible}.concept-visual{break-inside:avoid}}