:root{--paper:#f4f7fa;--white:#fff;--ink:#24323f;--muted:#536574;--line:#d8e1e8;--blue:#2363bb;--teal:#087e75;--warm:#d9a145;--display:"Microsoft YaHei UI","Microsoft YaHei",sans-serif;--body:"Segoe UI","Microsoft YaHei",sans-serif;--data:"Cascadia Mono",Consolas,monospace}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.7}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}button,input,select{font:inherit}button,select,a.primary{touch-action:manipulation}button{cursor:pointer;background:var(--white);border:1px solid #c3d1dc;border-radius:8px;padding:9px 13px;color:var(--ink)}button:hover{border-color:var(--blue);background:#f0f6fd}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible,#bookGroup:focus-visible{outline:3px solid 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var(--data);fill:var(--teal)}.load-label{fill:var(--blue)}#bookGroup{cursor:grab;touch-action:none}#bookGroup.dragging{cursor:grabbing}.model-caption{font-size:11px;color:var(--muted);margin:0;padding:0 23px}.shelf-controls{padding:27px 28px;border-left:1px solid var(--line)}.shelf-controls h2{font-size:22px}.quiet{font-size:13px;color:var(--muted)}.shelf-controls>.quiet{margin:9px 0 20px}.shelf-controls>label{display:block;font-size:14px}.shelf-controls output{float:right;color:var(--blue);font-family:var(--data);font-weight:600}input[type=range]{display:block;width:100%;margin:20px 0 17px;accent-color:var(--blue);cursor:ew-resize;min-height:22px}.position-buttons{display:flex;justify-content:space-between;gap:7px;margin-bottom:18px}.position-buttons button{font-size:13px;flex:1;padding:7px 2px}.primary{display:inline-flex;align-items:center;justify-content:center;gap:18px;background:var(--blue);color:white;border:1px solid var(--blue);border-radius:8px;padding:12px 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.primary{white-space:nowrap}.after-lesson>details{padding:20px 0}.after-lesson summary{font-size:16px}.after-lesson summary span{font-weight:400;color:var(--muted);font-size:13px;margin-left:16px}.quiz-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:25px;padding-top:24px}fieldset{border:0;margin:0;padding:0;min-width:0}legend{font-size:15px;font-weight:600;padding:0}fieldset>p,fieldset>label{font-size:14px}fieldset>label{display:flex;align-items:baseline;gap:8px;margin:12px 0}input[type=radio]{accent-color:var(--teal)}.number-answer{flex-wrap:wrap}.number-answer input{width:100px;min-width:0;border:1px solid #b9cad7;padding:7px;border-radius:5px}.quiz-feedback{border-left:3px solid var(--teal);padding-left:11px;color:var(--teal);font-size:13px}.quiz-feedback:empty{display:none}.quiz-feedback[data-correct=false]{border-color:#a87220;color:#7e571b}.script-text{max-width:780px;margin:25px auto}.script-text p{font-size:16px;line-height:2.05;margin:0 0 21px}.outline-content{max-width:800px;padding:25px 0}.outline-lead{font-size:21px;line-height:1.75;color:#475c6d;margin-top:0}.outline-content section{margin:28px 0}.outline-content h2{font-size:18px;margin-bottom:10px}.outline-content section p{font-size:15px}.available-lab{padding:24px;background:var(--white);border:1px solid var(--line);border-radius:12px}.available-lab>.quiet{margin-bottom:0}.outline-content>button{margin-top:20px}footer{font-size:12px;color:var(--muted);padding:30px 0 36px;border-top:1px solid var(--line);margin-top:26px}button,select,.primary{transition:background-color .12s,border-color .12s}@media(max-width:950px){.course-intro{align-items:flex-start;flex-direction:column;gap:15px}.course-intro select{width:min(460px,65vw);max-width:460px}.shelf-stage{grid-template-columns:minmax(0,1.5fr) minmax(255px,1fr)}.shelf-controls{padding:22px 20px}.site-header,main{padding-left:24px;padding-right:24px}h1{font-size:29px}.model-caption{padding:0 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h2{font-size:21px}.bridge-step{align-items:flex-start;flex-direction:column;gap:18px;padding:22px 0}.bridge-step h2{font-size:22px}.after-lesson summary span{display:block;margin:5px 0 0 18px;font-size:12px}.after-lesson summary{font-size:14px}.script-text p{font-size:15px}.outline-lead{font-size:18px}.available-lab{padding:19px}.site-header>a:last-child{font-size:12px}footer{font-size:11px}}@media(prefers-reduced-motion:reduce){button,select,.primary{transition:none}}

@media(max-width:680px){.site-header{height:68px}.course-intro{padding-top:13px;padding-bottom:15px}.lesson-heading{margin-bottom:15px}h1{font-size:26px}#shelfSvg{min-height:0}.shelf-controls{display:flex;flex-direction:column;padding-top:16px}.shelf-controls>.primary{order:4;margin-top:10px}.prediction{order:5;margin-top:15px}.live-result{order:6}#whyPanel{order:7}.position-buttons{margin-bottom:0}}