:root{color-scheme:dark;--paper:#20211f;--ink:#f3f0e7;--muted:#c0c1b8;--line:#62675c;--surface:#292d26;--accent:#bbd1ca;--button-ink:#202923;--warm:#edce8f}
:root[data-theme="light"]{color-scheme:light;--paper:#f8f6ee;--ink:#262c27;--muted:#535c50;--line:#8c9484;--surface:#eceee4;--accent:#365f53;--button-ink:#fff;--warm:#725006}
*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:1rem/1.6 "Segoe UI",system-ui,sans-serif}header,main,footer{max-width:1020px;margin:auto;padding-inline:1.6rem}button,select,input{font:inherit}button,select,input[type=number]{min-height:46px;border:1px solid var(--line);background:var(--paper);color:var(--ink);padding:.5rem .8rem;border-radius:3px;max-width:100%}button{cursor:pointer;touch-action:manipulation}button:disabled{opacity:.45;cursor:default}button:hover:not(:disabled){background:var(--surface)}a{color:inherit;text-underline-offset:4px}a:hover,summary:hover{color:var(--accent)}a:focus-visible,button:focus-visible,select:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:4px}[hidden]{display:none!important}.skip{position:absolute;left:1rem;top:-100px;padding:.7rem;background:var(--accent);color:var(--button-ink);z-index:3}.skip:focus{top:.5rem}.bar{display:flex;justify-content:space-between;align-items:center;gap:1rem;border-bottom:1px solid var(--line);padding:.8rem 0}.bar a{min-height:44px;display:inline-flex;align-items:center}.theme{border:0;background:none;text-decoration:underline;text-underline-offset:4px}.crumb{font-size:.88rem;color:var(--muted);margin:1.2rem 0 0;overflow-wrap:anywhere}h1{font:600 clamp(2rem,5.5vw,3.25rem)/1.13 Georgia,serif;letter-spacing:-.025em;margin:1.1rem 0}h2{font-size:1.3rem;line-height:1.35;margin:0 0 .7rem}h3{font-size:1rem;margin:1rem 0 .4rem}p{max-width:48rem;margin:.65rem 0 1rem}.lead{color:var(--muted);margin-bottom:1.8rem}.chapter-nav{display:flex;flex-wrap:wrap;gap:0 1.4rem;border-block:1px solid var(--line);margin:1.5rem 0}.chapter-nav a{min-height:48px;display:flex;align-items:center}.chapter-nav a[aria-current=page]{font-weight:600;text-decoration-thickness:3px}.instruction{max-width:49rem}.settings{display:flex;flex-wrap:wrap;gap:.65rem 1rem;align-items:center;margin:1rem 0}.settings label{font-size:.92rem}.settings small{color:var(--muted)}.values{display:flex;flex-wrap:wrap;gap:.6rem 1.8rem;margin:1.5rem 0 .5rem}.value{min-width:0}.value>span{display:block;color:var(--muted);font-size:.85rem}.value output{font:600 1.6rem Consolas,monospace;color:var(--warm)}.value code{overflow-wrap:anywhere}.value .count{font-size:1.3rem}.condition{font-size:.9rem;color:var(--muted);margin:.2rem 0 1rem}.condition strong{color:var(--ink)}.controls{display:flex;flex-wrap:wrap;gap:.6rem;margin:.8rem 0}.primary{background:var(--accent);color:var(--button-ink);border-color:var(--accent);font-weight:600}.primary:hover:not(:disabled){background:var(--accent);filter:brightness(.93)}figure{margin:1rem 0}.scene canvas{display:block;width:100%;height:auto;aspect-ratio:16/9;border:1px solid var(--line);background:#fff}.scene figcaption{display:flex;justify-content:space-between;flex-wrap:wrap;gap:.25rem 1rem;color:var(--muted);font-size:.82rem;margin-top:.3rem}.status{min-height:3.2em}.subtle{font-size:.9rem;color:var(--muted)}.rule{border-left:3px solid var(--accent);padding-left:1rem;margin:1.5rem 0}.exercise{padding:1.6rem 0;border-top:1px solid var(--line)}.order{max-width:44rem;padding-left:1.5rem}.order li{margin-bottom:.8rem}.order label{display:block}.order select{width:100%;margin-top:.25rem}.answer{min-height:2em;color:var(--warm)}details{border-top:1px solid var(--line)}details:last-of-type{border-bottom:1px solid var(--line)}summary{min-height:50px;padding:.9rem .1rem;cursor:pointer;font-weight:600}details>div{padding:0 .1rem 1rem}pre{font:.95rem/1.7 Consolas,"Cascadia Mono",monospace;white-space:pre;overflow:auto;background:var(--surface);border-left:3px solid var(--accent);padding:1rem;margin:.65rem 0 1rem;tab-size:4}code{font-family:Consolas,"Cascadia Mono",monospace}.code-part{display:block;min-width:max-content}.code-part.active{background:var(--paper);outline:1px solid var(--accent);outline-offset:2px}.code-part.active::before{content:""}.phase-label{font-size:.9rem;color:var(--warm);min-height:1.6em}table{width:100%;border-collapse:collapse;font-size:.92rem;font-variant-numeric:tabular-nums}th,td{text-align:left;border-bottom:1px solid var(--line);padding:.65rem .45rem}caption{text-align:left;color:var(--muted);margin:.5rem 0}th code{font-size:.85em}th{vertical-align:bottom}.table-wrap{overflow:auto}.materials{display:flex;flex-wrap:wrap;gap:.4rem 1.6rem;margin-top:1.2rem}.materials a{display:flex;align-items:center;min-height:46px}.pairlinks{display:flex;justify-content:space-between;gap:1rem;margin:1.5rem 0}.pairlinks a{min-height:46px;display:flex;align-items:center}footer{margin-top:2rem;padding-bottom:2rem;font-size:.82rem;color:var(--muted)}footer p{border-top:1px solid var(--line);padding-top:1rem}.noscript{padding:1rem;border:1px solid var(--line)}.definitions{display:grid;grid-template-columns:max-content 1fr;gap:.65rem 1.2rem;max-width:48rem}.definitions dt{font-weight:600}.definitions dd{margin:0}.note{border-top:1px solid var(--line);padding-top:1rem}.name-pair{display:block;font-size:.82rem;color:var(--muted)}
@media(max-width:620px){header,main,footer{padding-inline:1rem}.bar{font-size:.9rem}.controls button{flex:1 1 130px;padding:.55rem}.controls button:last-child{flex-basis:100%}.chapter-nav{font-size:.9rem;gap:0 1rem}.values{gap:.6rem 1.15rem}.value output{font-size:1.3rem}.value code{font-size:.88rem}.value>span{font-size:.8rem}pre{font-size:.83rem;padding:.8rem}th,td{font-size:.82rem;padding:.6rem .35rem}.settings{align-items:flex-start}.settings small{flex-basis:100%}.definitions{grid-template-columns:1fr;gap:.2rem}.definitions dd{margin-bottom:.5rem}.phase-label{min-height:3.2em}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
@media print{:root{--paper:#fff;--ink:#222;--muted:#444;--line:#999;--surface:#eee;--accent:#333;--warm:#333}header,.chapter-nav,.controls,.settings,.pairlinks,.materials,.skip{display:none!important}body{font-size:11pt}main{max-width:none;padding:0}h1{font-size:25pt}.scene,.exercise{break-inside:avoid}details>div{display:block!important}footer{padding:0}.code-part.active{outline:0}}
