:root{color-scheme:dark;--bg:#121b23;--panel:#1a252f;--line:#34434e;--ink:#e9edf0;--muted:#a6b6c2;--amber:#edb45e;--blue:#73cde7}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:20px}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.6 system-ui,-apple-system,sans-serif}button,input,a{-webkit-tap-highlight-color:transparent}button,input{font:inherit}button{min-height:42px;cursor:pointer;background:transparent;border:1px solid var(--line);color:var(--ink);padding:8px 14px;border-radius:3px;line-height:1.3}button:hover{background:#2d3b45}button.active{background:var(--ink);color:var(--bg);border-color:var(--ink)}button:focus-visible,a:focus-visible,input:focus-visible,canvas:focus-visible{outline:3px solid var(--blue);outline-offset:3px}a{color:var(--blue);text-underline-offset:4px}header,main,footer{max-width:1600px;margin:auto}header{display:flex;gap:22px;align-items:center;padding:26px 36px 20px;border-bottom:1px solid var(--line)}.stamp{font:13px/1.4 monospace;border:1px solid var(--amber);color:var(--amber);padding:6px 12px;letter-spacing:2px}.stamp strong{font-size:25px}.eyebrow{font:12px/1.4 ui-monospace,SFMono-Regular,Consolas,monospace;letter-spacing:2px;margin:0 0 8px;color:var(--amber)}h1{font:500 clamp(26px,3vw,43px)/1.15 Georgia,serif;letter-spacing:-1px;margin:0}h2{font:500 28px/1.2 Georgia,serif;margin:6px 0 14px}h3{font-size:18px;margin:24px 0 10px}p{margin:0 0 16px}.source-link{margin-left:auto;font-size:14px}main{padding:0 36px}.intro{display:flex;justify-content:space-between;gap:20px;align-items:center;padding:20px 0}.intro p{margin:0}.intro>span{font:12px/1.5 monospace;color:var(--muted);max-width:190px}.workspace{display:grid;grid-template-columns:minmax(0,1fr) 330px;border:1px solid var(--line);background:#15202a}.viewbar{display:flex;justify-content:space-between;gap:8px;padding:12px 14px;border-bottom:1px solid var(--line)}.buttonset{display:flex;gap:5px}.viewbar button{font-size:14px;min-height:36px;padding:7px 12px}.model-side{min-width:0}#viewer{height:560px;position:relative;overflow:hidden;background:#111c26}#scene{display:block;width:100%;height:100%;touch-action:none}#labels{position:absolute;inset:0;pointer-events:none;overflow:hidden}.model-label{position:absolute;transform:translate(-50%,-50%);font:12px/1.3 monospace;color:#f6d9ad;background:#13202cdd;padding:3px 5px;white-space:nowrap}.model-badge{position:absolute;left:18px;top:16px;pointer-events:none;font:12px/1.4 monospace;letter-spacing:1px}.model-badge small{display:block;color:var(--muted);font-size:12px;letter-spacing:0;margin-top:4px}.scale-key{position:absolute;left:18px;bottom:42px;display:flex;gap:14px;font-size:12px;pointer-events:none}.key:before{content:'';display:inline-block;width:12px;height:3px;vertical-align:middle;margin-right:6px;background:var(--ink)}.key.wood:before{background:#a77c4f}.key.load:before{background:var(--blue)}.gesture{position:absolute;left:18px;bottom:16px;font-size:12px;color:var(--muted);pointer-events:none}.layerbar{padding:9px 14px;display:flex;gap:18px;flex-wrap:wrap;border-top:1px solid var(--line);font-size:14px}.layerbar label{display:flex;align-items:center;gap:6px;cursor:pointer}input[type=checkbox]{accent-color:var(--amber);width:17px;height:17px}.transport{display:flex;gap:16px;align-items:center;padding:10px 14px}.primary{background:var(--amber);color:#151c23;border-color:var(--amber);font-weight:650;white-space:nowrap}.primary:hover{background:#ffd18b}.transport input{flex:1;min-width:40px}.transport output{font:14px monospace;min-width:40px}input[type=range]{accent-color:var(--amber);cursor:pointer;width:100%;height:25px;margin:7px 0}.footnote{font-size:12px;color:var(--muted);padding:0 14px;margin:0 0 14px}.sequence{padding:22px;border-left:1px solid var(--line);background:var(--panel)}#stages{display:grid;gap:0;margin-bottom:24px}#stages button{text-align:left;display:flex;align-items:center;gap:12px;border:0;border-bottom:1px solid #34434e;min-height:44px;border-radius:0;font-size:14px;padding:10px 4px}#stages button span{font:12px monospace;color:var(--muted)}#stages button.active{background:transparent;color:var(--amber);box-shadow:inset 3px 0 var(--amber);padding-left:12px}#stages button.active span{color:var(--amber)}.tag{display:inline-block;font:12px/1.5 monospace;color:var(--blue);letter-spacing:.5px}.stage-copy h2{font-size:25px}.stage-copy p{font-size:15px}.muted{color:var(--muted);font-size:14px}.live-pair{display:grid;grid-template-columns:1fr 1fr;gap:12px;border-block:1px solid var(--line);padding:13px 0;margin:18px 0}.live-pair span{display:block;font-size:12px;color:var(--muted)}.live-pair strong{font:24px/1.5 ui-monospace,monospace;white-space:nowrap}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:25px;margin-bottom:22px}.section-heading>p{font-size:14px;text-align:right;margin:0}.engineering,.record{padding:44px 0}.calc-tabs{display:flex;gap:8px;border-bottom:1px solid var(--line);padding-bottom:14px}.calc-tabs button{font-size:14px}.calc-panel{display:grid;grid-template-columns:320px 1fr;border:1px solid var(--line);border-top:0;background:var(--panel)}[hidden]{display:none!important}.inputs{padding:26px;border-right:1px solid var(--line)}.inputs label{display:block;font-size:14px;margin-bottom:13px}.inputs output{float:right;font:14px monospace;color:var(--amber)}.inputs .muted{font-size:13px;line-height:1.6;margin-top:15px}.calc-results{padding:26px;min-width:0}.result-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:24px}.result{padding-bottom:16px;border-bottom:1px solid var(--line)}.result span{display:block;font-size:13px;color:var(--muted)}.result strong{font:clamp(21px,2.6vw,34px)/1.4 ui-monospace,monospace;color:var(--amber);white-space:nowrap}.result small{font-size:12px;color:var(--muted)}.formula{font:15px/2 ui-monospace,monospace;background:#101a24;padding:16px 20px;margin:20px 0;border-left:2px solid var(--blue)}.scope-note{font-size:13px;color:var(--muted);margin:14px 0 0}.force-diagram svg{width:100%;height:190px}.force-diagram text,#torque-chart text{fill:var(--muted);font:14px monospace}#torque-chart{width:100%;max-height:210px}.record{border-top:1px solid var(--line)}.record-grid{display:grid;grid-template-columns:1.15fr .85fr;gap:50px}.record-grid h3:first-child{margin-top:0}.table-scroll{overflow:auto}table{border-collapse:collapse;width:100%;font-size:14px;line-height:1.5}th,td{text-align:left;padding:10px;border-bottom:1px solid var(--line)}th{color:var(--muted);font-weight:500}.plates img{display:block;width:100%;max-height:720px;object-fit:contain;background:#e9e9e6}.plates p{font-size:13px;color:var(--muted);margin-top:12px}.sources{margin-top:28px;max-width:1050px}.sources p{font-size:14px;color:var(--muted)}footer{padding:26px 36px;border-top:1px solid var(--line);font:12px monospace;color:var(--muted);display:flex;justify-content:space-between}.sr-only{position:absolute;clip:rect(0,0,0,0);width:1px;height:1px;overflow:hidden}.secondary{border-color:var(--amber);color:var(--amber);width:100%}#render-error{position:absolute;inset:80px 25px auto;padding:25px;background:#402d1c}
@media(min-width:1450px){#viewer{height:610px}}@media(max-width:1050px){header{padding:22px}.workspace{grid-template-columns:minmax(0,1fr) 280px}main{padding:0 22px}.sequence{padding:16px}.live-pair strong{font-size:20px}.calc-panel{grid-template-columns:280px 1fr}.result-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:760px){header{gap:14px;padding:18px 16px}.stamp{padding:4px 8px}.stamp strong{font-size:22px}.eyebrow{font-size:11px;letter-spacing:1.3px}h1{font-size:29px}.source-link{font-size:12px;max-width:68px;text-align:right}main{padding:0 12px}.intro{padding:15px 3px}.intro p{font-size:14px}.intro>span{display:none}.workspace{display:flex;flex-direction:column}.viewbar{padding:9px 8px;gap:4px}.viewbar button{font-size:12px;padding:7px 9px}.buttonset{gap:4px}#viewer{height:430px}.model-badge{left:12px;top:12px;font-size:11px}.scale-key{left:12px;font-size:10px;gap:10px}.gesture{left:12px;font-size:11px}.layerbar{padding:9px;gap:10px;font-size:12px}.transport{padding:10px;gap:10px}.transport button{font-size:13px;padding:9px}.sequence{border-top:1px solid var(--line);border-left:0;padding:18px}#stages{grid-template-columns:repeat(4,1fr);gap:6px;margin-bottom:18px}#stages button{display:block;padding:8px 4px;font-size:11px;text-align:center;border:1px solid var(--line)}#stages button span{display:block;font-size:10px}#stages button.active{box-shadow:inset 0 -2px var(--amber);padding-left:4px}.stage-copy h2{font-size:25px}.stage-copy .live-pair{margin:12px 0}.stage-copy p:last-child{margin-bottom:0}.section-heading{display:block}.section-heading>p{text-align:left;font-size:14px}.engineering,.record{padding:32px 0}.section-heading h2{font-size:27px}.calc-tabs{gap:5px}.calc-tabs button{font-size:12px;flex:1;padding:9px 5px}.calc-panel{display:flex;flex-direction:column}.inputs{border-right:0;border-bottom:1px solid var(--line);padding:20px}.calc-results{padding:20px}.result-grid{gap:12px}.result strong{font-size:26px}.result span{font-size:12px}.record-grid{display:flex;flex-direction:column;gap:28px}td,th{font-size:12px;padding:9px 6px}.plates img{max-height:650px}.formula{font-size:13px;padding:14px}.record-grid p,.calc-results p{font-size:15px}footer{padding:20px 14px;display:block}footer span{display:block;margin-top:8px}}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* Shared navigation back to the parent site. */
body > .field-notes-return{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:4px 24px;margin:0 auto;padding:6px clamp(16px,3vw,36px);border-bottom:1px solid #34434e;background:#10181f;font:14px/1.5 ui-monospace,SFMono-Regular,Consolas,monospace}body > .field-notes-return a{display:inline-flex;align-items:center;min-height:44px;color:#bce9f5;text-decoration:underline;text-underline-offset:4px}body > .field-notes-return a:hover{color:#fff}body > .field-notes-return a:focus-visible{outline:3px solid #ffc763;outline-offset:3px}

.playback-options{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px;padding:0 14px 12px}.playback-options label{display:flex;align-items:center;gap:10px;font-size:14px;color:var(--muted)}.playback-options select{font:inherit;background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:3px;min-height:44px;padding:8px 12px}.playback-options button{font-size:14px}.playback-options select:focus-visible{outline:3px solid var(--blue);outline-offset:3px}

.field-notes-return a.research-link{display:inline-flex;align-items:center;min-height:44px;padding:8px 14px;border:1px solid var(--amber);border-radius:3px;color:var(--amber);font-weight:600}

.wheel-history{border-top:1px solid var(--line);padding:44px 0}.history-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:30px}.history-grid article{padding:24px;background:var(--panel);border:1px solid var(--line)}.history-grid h3{font:500 24px/1.25 Georgia,serif;margin:12px 0 18px}.history-grid p{font-size:16px;line-height:1.65}.history-grid p:last-child{margin-bottom:0}.history-grid .eyebrow{font-size:12px;line-height:1.4}.history-grid a{font-size:13px;white-space:nowrap}.history-sources{max-width:1100px}@media(max-width:1050px){.history-grid{grid-template-columns:1fr;gap:16px}.history-grid article{padding:22px}.wheel-history{padding:32px 0}}

.sample-plan{margin:48px 0;padding:28px;border:1px solid #465662;border-top:4px solid #edb45e;scroll-margin-top:20px}.sample-plan p{max-width:100ch;line-height:1.6}.plan-controls{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;margin:28px 0}.plan-controls label{display:flex;flex-direction:column;gap:10px;font-size:16px}.plan-controls output{color:#edb45e;font-size:24px}.plan-controls input[type=number]{width:100%;padding:12px;background:#121b23;color:#fff;border:1px solid #647784;font:inherit}.plan-table{width:100%;min-width:760px}.plan-table td{vertical-align:top;line-height:1.5}.plan-table button{text-align:left;color:#edb45e;white-space:normal;font-size:15px}.plan-track{width:140px;height:8px;background:#273642;margin-top:12px}.plan-track i{display:block;height:8px;background:#73cde7}.plan-detail-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin:28px 0}.sample-plan summary{font-size:18px;cursor:pointer;padding:16px 0}.sample-plan li{margin:12px 0;line-height:1.6}@media(max-width:700px){.sample-plan{padding:18px 12px}.plan-controls{grid-template-columns:1fr 1fr;gap:18px}.plan-detail-grid{grid-template-columns:1fr}.sample-plan .section-heading{display:block}}@media print{body{background:white!important;color:black!important}body>nav,body>header,.intro,.workspace,.engineering,.record,.wheel-history,footer{display:none!important}.sample-plan{border:0;margin:0;padding:0}.sample-plan *{color:black!important}.sample-plan button{border:0;background:none}.sample-plan #print-plan,.plan-controls input{display:none}.plan-detail-grid{display:block}.table-scroll{overflow:visible}.plan-table{min-width:0;font-size:11px}.sample-plan details{display:block}.sample-plan details>*{display:block}.sample-plan .result strong{font-size:20px}article,tr{break-inside:avoid}}

.study-jumps{display:flex;gap:12px;flex-wrap:wrap;padding:20px 0}.study-jumps a{border:1px solid var(--line);padding:8px 12px;font-size:14px}.history-extension{padding:36px 0;border-top:1px solid var(--line)}.date-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0}.date-strip article{padding:16px;border:1px solid var(--line)}.date-strip strong,.date-strip span{display:block}.date-strip span{font-size:14px;color:var(--muted)}.telegram-note{border-left:3px solid var(--amber);padding:16px 22px;background:var(--panel);margin:24px 0}.history-controls{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin:24px 0}.history-controls label{font-size:14px}.history-controls output{display:block;color:var(--amber);font-family:monospace}.history-chart-scroll{overflow-x:auto;margin:24px 0}.history-chart-scroll svg{display:block;width:100%;min-width:850px;background:var(--panel)}#history-gantt text{fill:var(--ink);font:14px monospace}.history-extension details{padding:18px;border:1px solid var(--line);margin:20px 0}.history-extension summary{cursor:pointer;margin-bottom:12px}.foundation-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:24px}.foundation-layout>div{min-width:0}.foundation-toolbar{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:14px}.foundation-toolbar label{padding:8px}#foundation-viewer{height:440px;position:relative;margin-top:12px;background:#111c26}#foundation-scene{width:100%;height:100%;display:block;touch-action:none}.foundation-caption{position:absolute;top:14px;left:16px;font:12px/1.7 monospace;pointer-events:none;background:#111c26cc;padding:8px}.foundation-slider{display:flex;align-items:center;gap:14px;padding:12px 0;white-space:nowrap;font-size:14px}.foundation-key{display:flex;gap:16px;flex-wrap:wrap;font-size:14px;color:var(--muted)}#foundation-steps{display:grid;gap:4px}#foundation-steps button{text-align:left;font-size:14px}.trades-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:12px 30px}.history-extension .result-grid{grid-template-columns:repeat(3,1fr)}@media(max-width:800px){.foundation-layout{grid-template-columns:1fr}.history-controls{grid-template-columns:1fr;gap:8px}.date-strip{grid-template-columns:repeat(2,1fr)}.trades-grid{grid-template-columns:1fr}.history-extension .result-grid{grid-template-columns:1fr}.foundation-caption{font-size:12px}#foundation-viewer{height:360px}}