:root{--ink:#24343e;--muted:#68757b;--paper:#fcfbf7;--line:#dce2df;--accent:#196d69;--rust:#a95634;--panel:#fff;--shadow:0 8px 32px #213f5312;--serif:Georgia,'Times New Roman',serif;--sans:system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif}
[hidden]{display:none!important}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--serif);font-size:17px;line-height:1.75}a{color:var(--accent);text-decoration-thickness:1px;text-underline-offset:3px}button,input,select{font:inherit}button,select{cursor:pointer}button{border:1px solid var(--line);background:#fff;border-radius:5px;padding:5px 10px;color:var(--ink)}button:hover{background:#eef5f3;border-color:#aabfbb}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #dba552;outline-offset:3px}.page{max-width:1400px;margin:auto;padding:34px 48px 65px}.article-header{margin:0 0 35px;max-width:1100px}.back{font:13px var(--sans)}.eyebrow{font:11px var(--sans);letter-spacing:.19em;text-transform:uppercase;color:var(--accent);margin:36px 0 9px}h1{font-size:clamp(42px,5vw,68px);font-weight:400;letter-spacing:-.04em;line-height:1.06;margin:0 0 16px}.subtitle{font-size:23px;line-height:1.45;margin:0 0 18px;color:#52646e}.byline{font:12px/1.6 var(--sans);color:var(--muted)}.status-strip{display:flex;gap:8px;align-items:center;flex-wrap:wrap;font:12px/1.6 var(--sans);border-top:1px solid var(--line);padding-top:12px;margin-top:23px}.status-strip a{margin-left:6px}.status-dot{width:7px;height:7px;background:#bf9141;border-radius:50%;display:inline-block}.reading-layout{display:grid;grid-template-columns:minmax(0,1fr) minmax(380px,1.08fr);gap:52px;align-items:start}article{min-width:0;max-width:650px}article section{margin-bottom:55px;scroll-margin-top:30px}article p{margin:0 0 20px}.lead{font-size:21px;line-height:1.65}h2{font-size:27px;line-height:1.3;font-weight:400;margin:30px 0 20px;letter-spacing:-.02em}.instruction{font:13px/1.7 var(--sans);color:var(--muted);border-left:2px solid #bbd4cc;padding-left:15px}.inline-action{display:inline;border:0;border-bottom:1px dotted var(--accent);border-radius:0;padding:0;background:transparent;color:var(--accent);font:inherit}.equation{font-size:21px;text-align:center;line-height:1.6;margin:25px 0;overflow:auto;padding:9px 0;white-space:normal}.equation-arrow{font:12px var(--sans);color:var(--muted)}.frac{display:inline-flex;flex-direction:column;vertical-align:middle;text-align:center;line-height:1.5;margin:0 8px}.frac>span:first-child{border-bottom:1px solid;padding:0 8px}.note{font:14px/1.8 var(--sans);border-left:3px solid #b3c9bf;background:#f1f4ed;padding:17px 18px;margin:25px 0}.source-link{font:12px var(--sans)}.ref{font:12px var(--sans)}code,pre{font:12px/1.8 ui-monospace,SFMono-Regular,Consolas,monospace}pre{background:#edf1ec;padding:17px;border-radius:6px;overflow:auto}.ledger{border-collapse:collapse;font:13px/1.7 var(--sans);width:100%;margin:22px 0}.ledger th{text-align:left;font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}.ledger td,.ledger th{padding:12px 10px;border-bottom:1px solid var(--line);vertical-align:top}.ledger td:first-child{width:28%}.verification-note{font:13px/1.7 var(--sans);background:#f5f0e5;border:1px solid #e0d8bd;border-radius:6px;padding:14px}.verification-note.verified{background:#eef5ed;border-color:#c4d6c6}.ending{margin-top:40px!important;font-style:italic;font-size:21px;color:var(--accent)}
.demo-column{position:sticky;top:16px;min-width:0}.demo-card{background:var(--panel);border:1px solid #cbd6d1;border-radius:9px;box-shadow:var(--shadow);font:12px/1.5 var(--sans);overflow:auto;max-height:calc(100vh - 32px);transform:translate(var(--dx,0px),var(--dy,0px));resize:horizontal;min-width:360px;max-width:min(750px,calc(100vw - 40px));position:relative;z-index:5}.dragbar{display:flex;gap:8px;align-items:center;padding:9px 12px;border-bottom:1px solid var(--line);cursor:grab;background:#f7f9f5;touch-action:none}.dragbar .grip{font-size:18px;color:#99aaa3;line-height:1}.dragbar strong{font-weight:600;letter-spacing:.01em}.dragbar label{margin-left:auto;display:flex;align-items:center;gap:4px;font-size:10px;color:var(--muted);white-space:nowrap}.dragbar button{padding:0 6px;border:0;background:transparent;font-size:18px;line-height:1.2}.tabs{display:flex;border-bottom:1px solid var(--line);padding:0 8px;gap:2px}.tabs button{flex:1;border:0;border-radius:0;padding:10px 3px;background:none;font-size:11px;color:var(--muted)}.tabs button[aria-selected=true]{color:var(--accent);box-shadow:inset 0 -2px var(--accent);font-weight:600}.experiment-heading{display:flex;gap:7px;align-items:center;padding:10px 12px 7px}.experiment-heading span{font-weight:600;margin-right:auto;font-size:12px}.experiment-heading button{font-size:10px;padding:4px 8px;white-space:nowrap}.primary{background:var(--accent);color:white;border-color:var(--accent)}.primary:hover{background:#175956}.primary[aria-pressed=true]{background:#eff6ef;border-color:#94b4a5;color:#316343}.controls{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;padding:0 13px 8px}.control{font-size:10px;color:var(--muted);min-width:0}.control span{float:right;color:var(--ink);font-variant-numeric:tabular-nums}.control input[type=range]{display:block;width:100%;margin:6px 0 0;accent-color:var(--accent);height:14px}.surface-controls{display:flex;gap:8px;grid-column:1/-1;align-items:center}.surface-controls button{font-size:10px}.stage{position:relative;background:#fafbf8;border-top:1px solid #e8ece7;border-bottom:1px solid #e8ece7;height:310px;overflow:hidden}canvas{display:block;width:100%;height:100%;touch-action:none}#cube{position:absolute;right:9px;top:8px;width:139px;height:122px;overflow:visible;background:#fafbf8dc;border-radius:7px}#cube text{font:10px var(--sans);pointer-events:none}#cube .cube-edge{cursor:pointer}#cube [role=button]{outline:none}#cube [role=button]:focus .node{stroke:#d99524;stroke-width:4}.stage.surface{height:252px}.stage.surface #cube{width:255px;height:225px;top:12px;left:calc(50% - 128px);background:none}.stage.surface canvas{display:none}.stage.bridge #cube{display:none}.stage-label{position:absolute;bottom:8px;left:12px;font:10px var(--sans);color:var(--muted);background:#fafbf8de;padding:2px 5px;pointer-events:none}.selection{padding:8px 12px;display:flex;align-items:center;gap:10px;font-size:10px;flex-wrap:wrap}.selection select{font-size:10px;max-width:155px;padding:3px 4px;background:#fff;border:1px solid var(--line);border-radius:4px;color:var(--ink)}.selection label{display:flex;gap:5px;align-items:center}.selection input{margin:0;accent-color:var(--accent)}.selection button{font-size:10px;margin-left:auto;padding:3px 7px}.readout{padding:9px 13px;background:#f4f7f2;border-top:1px solid #e3e9e1;font-size:11px;line-height:1.75;font-variant-numeric:tabular-nums;min-height:53px}.readout strong{font-weight:600;color:#2c6a59}.readout .warn{color:#98541e}.face-readout{display:grid;grid-template-columns:repeat(3,1fr);gap:5px;padding:7px 12px 0}.face-chip{font:10px/1.5 var(--sans);text-align:left;padding:4px 6px;background:#fcfdfb;min-width:0;font-variant-numeric:tabular-nums}.face-chip.active{background:#e8f2ec;border-color:#93b4a4}.face-chip.changed{color:var(--rust)}.face-readout.coefficients{grid-template-columns:repeat(3,1fr)}.coeff-cell{font:10px/1.5 ui-monospace,monospace;padding:3px 5px;background:#f5f6f2}.hint{color:var(--muted);font-size:10px;margin:8px 13px;line-height:1.6;min-height:28px}.panel-footer{padding:8px 12px;border-top:1px solid var(--line);display:flex;align-items:center;gap:9px;font-size:9px;color:var(--muted)}.panel-footer button{font-size:9px;padding:2px 6px;margin-left:auto}.panel-footer a{white-space:nowrap}
@media(min-width:1500px){.stage{height:340px}.page{max-width:1450px}.reading-layout{gap:65px}}@media(max-width:1100px){.page{padding:25px 26px}.reading-layout{gap:28px;grid-template-columns:minmax(0,1fr) minmax(360px,1fr)}.subtitle{font-size:20px}.byline{font-size:11px}.stage{height:280px}.controls{gap:6px}.experiment-heading span{font-size:11px}}@media(max-width:820px){.page{padding:23px 20px}.reading-layout{display:flex;flex-direction:column;gap:30px}.demo-column{position:static;order:-1;width:100%}.demo-card{min-width:0;width:100%!important;max-width:none;max-height:none;resize:none;transform:none}.dragbar{cursor:default}.dragbar .grip{display:none}.dragbar label{display:none}article{max-width:680px;margin:auto}.stage{height:330px}.article-header{margin-bottom:24px}.eyebrow{margin-top:25px}.status-strip{font-size:11px}.subtitle{font-size:19px}.wide{display:none}h2{font-size:26px}.lead{font-size:20px}}@media(max-width:450px){.page{padding:18px 14px}.stage{height:285px}#cube{width:115px;height:100px}.panel-footer{gap:6px}.panel-footer span{max-width:125px}.controls{gap:8px}.selection{gap:7px}.subtitle{font-size:18px}.ledger{font-size:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@media print{.demo-column{display:none}.reading-layout{display:block}article{max-width:none}.page{padding:0}.status-strip,.inline-action{display:none}}