:root{--bg:#f4f2ec;--ink:#202d33;--muted:#69777c;--line:#dadfdc;--accent:#c6603a;--nav:#172e36;--mint:#c9e1d8}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.7 "Segoe UI","Microsoft YaHei",sans-serif}button,input,select{font:inherit}button,a,input,summary{outline-offset:4px}button{cursor:pointer;border:1px solid var(--line);border-radius:6px;background:#fff;padding:7px 13px;color:inherit}button:hover{border-color:var(--accent)}button:disabled{opacity:.4;cursor:not-allowed}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}aside{width:260px;position:fixed;inset:0 auto 0 0;background:var(--nav);color:#dbe5e6;padding:30px 22px;overflow:auto}.brand{color:white;font-size:23px;letter-spacing:1px;font-weight:650;display:block}.brand small{display:block;font-size:10px;font-weight:400;letter-spacing:3px;margin:10px 0 0 35px;color:#9bb8b9}.mark{color:#f4ac79;font-size:30px;vertical-align:middle}.aside-note{font-size:12px;color:#9fb5b7;margin:26px 0}.search-label{font-size:11px;display:block;margin-bottom:6px;color:#9fb5b7}#search{width:100%;background:#25414a;border:1px solid #47616a;border-radius:5px;color:#fff;padding:10px;font-size:13px}nav{margin-top:24px}.nav-group{font-size:10px;letter-spacing:2px;color:#a3bdbe;margin:24px 0 10px}.nav-item{display:block;color:#c4d3d5;padding:10px 8px;border-radius:5px;font-size:12px;margin:4px 0}.nav-item.active{background:#d8e8df;color:#173c39}.nav-item .idx{font-size:10px;opacity:.6;display:inline-block;width:24px}.progress{padding-top:28px;font-size:11px;color:#adc4c5}progress{width:100%;height:5px;accent-color:#dca879}main{max-width:1460px;margin-left:260px;padding:28px 46px}header{display:flex;justify-content:space-between;align-items:center}.eyebrow{font-size:10px;letter-spacing:2px;color:var(--muted);text-transform:uppercase;margin:0 0 10px}.text-link{font-size:12px}.intro{position:relative;padding:48px 0 30px;display:grid;grid-template-columns:1fr 1fr;gap:0 50px;border-bottom:1px solid var(--line)}h1{font-size:clamp(36px,4vw,58px);line-height:1.25;font-weight:520;letter-spacing:-2px;margin:0}h1 em{font-style:normal;color:var(--accent)}.intro>p{align-self:center;max-width:430px;color:var(--muted);font-size:14px}.stats{display:flex;gap:40px;grid-column:1/3;margin-top:30px;font-size:11px;color:var(--muted)}.stats b{color:var(--ink);font-size:22px;font-weight:500;margin-right:6px}.scope{display:flex;gap:20px;padding:20px 0;font-size:12px;color:var(--muted);border-bottom:1px solid var(--line)}.scope b{white-space:nowrap;color:var(--accent);font-weight:500}.lesson-head{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-top:42px}h2{font-size:27px;font-weight:550;line-height:1.35;margin:0 0 16px}h3{font-size:18px;font-weight:550}.done{white-space:nowrap;font-size:12px}.done input{accent-color:var(--accent)}.summary{color:var(--muted);max-width:850px;font-size:14px;margin-bottom:26px}.workspace{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(240px,1fr);gap:26px}.screen{background:#111b20;aspect-ratio:16/9;position:relative;border-radius:8px;overflow:hidden}.screen img,.screen video{width:100%;height:100%;object-fit:contain}.screen img{cursor:zoom-in}.screen-tag{position:absolute;right:10px;top:10px;font-size:11px;background:#172e36;color:white;border:0}.caption{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:var(--muted);margin-top:8px}.caption button{padding:2px 6px;background:none;border:0;font-size:11px}.video-bar{display:flex;gap:12px;align-items:center;margin-top:17px}.button{cursor:pointer;display:inline-block;background:var(--nav);color:white;border-radius:5px;padding:8px 12px;font-size:11px;white-space:nowrap}#fileStatus{font-size:10px;color:var(--muted)}.frame-controls{display:flex;gap:7px;align-items:center;margin-top:10px;flex-wrap:wrap}.frame-controls button{font-size:11px;padding:6px 9px}#frameInfo{font-size:10px;flex:1;color:var(--muted)}select{border:1px solid var(--line);background:white;font-size:11px;border-radius:4px;padding:4px}.panel-label{font-size:12px;letter-spacing:1px;border-bottom:1px solid var(--line);padding-bottom:12px}.panel-label span{float:right;color:var(--muted)}#steps{list-style:none;padding:0;margin:0;max-height:490px;overflow:auto}#steps li{border-bottom:1px solid var(--line)}.step{border:0;border-radius:0;background:none;text-align:left;width:100%;padding:14px 6px;display:grid;grid-template-columns:46px 1fr;gap:12px}.step.active{background:#e2e9e2}.step time{color:var(--accent);font-size:11px}.step strong{font-size:13px;font-weight:600;display:block}.step p{font-size:11px;color:var(--muted);margin:4px 0 0}.tabs{display:flex;gap:25px;margin-top:34px;border-bottom:1px solid var(--line)}.tabs button{border:0;background:transparent;border-radius:0;padding:14px 0;font-size:13px}.tabs button[aria-selected=true]{border-bottom:2px solid var(--accent);color:var(--accent)}.micro{font-size:11px;color:var(--muted);margin:18px 0}.param-row{display:grid;grid-template-columns:1.1fr 1.2fr 1.4fr 78px;gap:18px;padding:18px 0;border-bottom:1px solid var(--line);align-items:start;font-size:12px}.param-row .node{color:var(--muted);font-size:10px;display:block;margin-bottom:3px}.param-row b{font-weight:550}.value{font-family:"Consolas",monospace;color:#225c59;overflow-wrap:anywhere}.purpose{font-size:11px;color:var(--muted)}.status{font-size:9px;display:block;margin-top:6px;color:var(--muted)}.evidence-btn{font-size:10px;padding:4px 8px}.tab-pane{padding-bottom:20px}.practice{padding:20px;background:#e1e9df;border-left:3px solid #618e79;margin:25px 0}.practice p{margin:0}details{padding:16px 0;border-bottom:1px solid var(--line);font-size:13px}summary{cursor:pointer}details p{color:var(--muted)}#unknownList{font-size:13px;line-height:2;color:var(--muted);padding-left:20px}#review{font-size:13px}#frameEvidence img{max-width:31%;margin:1%;cursor:zoom-in}#downloads{border-top:1px solid var(--line);padding:42px 0 24px;margin-top:25px}.download-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:25px;margin-top:26px}.download-grid>div{border-top:2px solid #8aa49d;padding-top:15px}.download-grid p{font-size:12px;color:var(--muted)}.download-grid a{font-size:12px}.number{font-size:12px;color:var(--accent)}footer{font-size:11px;color:var(--muted);border-top:1px solid var(--line);padding:25px 0 20px}dialog{max-width:96vw;max-height:96vh;border:0;padding:45px 10px 10px;background:#0e1c22;border-radius:8px}dialog::backdrop{background:#061218db}dialog img{max-width:92vw;max-height:82vh;display:block}dialog button{position:absolute;right:10px;top:7px;background:transparent;color:#fff;border:0;font-size:12px}[hidden]{display:none!important}.empty{padding:30px;color:var(--muted)}@media(min-width:1700px){main{margin-right:auto}}@media(max-width:1100px){aside{width:220px;padding:25px 16px}main{margin-left:220px;padding:24px}.workspace{grid-template-columns:1fr}.steps-panel{margin-top:8px}#steps{max-height:300px}.intro{gap:0 20px}}@media(max-width:720px){aside{position:relative;width:100%;padding:20px}aside .aside-note,.search-label,.progress{display:none}.brand{font-size:20px}.brand small{display:inline;font-size:8px;margin-left:14px}#search{margin-top:14px}nav{display:flex;overflow:auto;gap:5px;margin-top:10px}.nav-group{display:none}.nav-item{min-width:160px;font-size:11px}main{margin:0;padding:20px}.intro{grid-template-columns:1fr;padding-top:28px}.intro p{margin-top:22px}.stats{grid-column:auto;gap:17px;margin-top:15px}.stats b{font-size:18px}.scope{display:block}.scope b{display:block;margin-bottom:7px}h2{font-size:23px}.lesson-head{margin-top:28px}.param-row{grid-template-columns:1fr 1fr;gap:8px 15px}.purpose{grid-column:1/2}.download-grid{grid-template-columns:1fr}.tabs{gap:24px}.done{font-size:10px}.video-bar{align-items:flex-start}.frame-controls{gap:6px}h1{font-size:40px}}

.render-preview{width:100%;aspect-ratio:4/3;object-fit:contain;background:#111;border-radius:5px;margin-bottom:12px}

/* final deliverables */
.download-grid video{width:100%;aspect-ratio:4/3;background:#000;border-radius:10px}#downloads .download-grid{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}section[id]{scroll-margin-top:24px}ol li{margin-bottom:12px;line-height:1.8}

/* readback table */
table{width:100%;border-collapse:collapse}th,td{text-align:left;padding:8px;border-bottom:1px solid #cad3cd;overflow-wrap:anywhere}details .micro{overflow-wrap:anywhere}