:root{color-scheme:dark;--bg:#232438;--paper:#303149;--sidebar:#2b2b43;--ink:#eeeaf9;--muted:#c0bad3;--line:#50516a;--primary:#bfbcff;--on-primary:#302d5b;--soft:#403d63;--callout:#3b3d61;--correct:#5c6da0;--wrong:#866087;--pending:#7d6291}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:90px}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.85 Inter,"Segoe UI","Microsoft YaHei",sans-serif}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}button{cursor:pointer}a{color:var(--primary);text-decoration:none;text-underline-offset:4px}a:hover{text-decoration:underline}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:2px solid var(--primary);outline-offset:4px}h1,h2,h3,p{margin:0 0 14px}h1{font-size:clamp(28px,3.5vw,40px);line-height:1.35;letter-spacing:-.025em;font-weight:650}h2{font-size:22px;line-height:1.5;font-weight:600}h3{font-size:17px;font-weight:600}small,.small{font-size:13px}.muted{color:var(--muted)}.breadcrumb{font-size:13px;color:var(--muted);margin-bottom:20px}
body>header{background:var(--paper);border-bottom:1px solid var(--line)}body>header>div{max-width:1360px;min-height:88px;margin:auto;padding:18px 32px;display:flex;gap:30px;align-items:center;flex-wrap:wrap}.brand{font-size:20px;font-weight:650;color:var(--ink);white-space:nowrap}.brand b{background:var(--primary);color:var(--on-primary);padding:6px 10px;border-radius:9px;margin-right:8px}body>header nav{display:flex;gap:22px;flex-wrap:wrap;font-size:14px}body>header nav a{color:var(--muted)}body>header nav a[aria-current=page]{color:var(--primary);font-weight:600}body>header form{margin-left:auto}body>header button{background:transparent;border:0;color:var(--muted);font-size:13px}.site-main{max-width:1320px;padding:34px 32px 70px;margin:auto;min-width:0}button,.primary{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:8px 17px;border:1px solid var(--line);border-radius:8px;background:var(--paper);color:var(--ink)}button:hover{background:var(--soft)}.primary{background:var(--primary);border-color:var(--primary);color:var(--on-primary);font-weight:600}.primary:hover{background:#d2cfff;text-decoration:none}button:disabled{opacity:.65;cursor:wait}.actions{display:flex;gap:18px;align-items:center;flex-wrap:wrap;margin-top:20px}
.cards,.course-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px;margin:26px 0}.card,.panel{background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:24px}.card{color:var(--ink)}.card strong{display:block;font-size:38px;font-weight:600;color:var(--primary)}.panel{margin:22px 0}.panel h2,.panel h3{margin-top:0}section>h2{margin-top:28px}details{background:var(--paper);border:1px solid var(--line);border-radius:9px;padding:16px 20px;margin:12px 0}summary{cursor:pointer;font-weight:500}summary small{color:var(--muted);font-weight:400;margin-left:8px}details[open]>summary{margin-bottom:18px}.scroll{overflow:auto}table{width:100%;border-collapse:collapse;font-size:14px}th,td{padding:13px;text-align:left;border-bottom:1px solid var(--line)}th{background:var(--soft);font-weight:500}.chapter,.appendix{background:var(--soft);font-weight:600}.subsection td:first-child{padding-left:35px}.section td:first-child{padding-left:22px}dl{display:grid;grid-template-columns:minmax(75px,max-content) 1fr;gap:7px 18px}dt{color:var(--muted)}dd{margin:0}ul{padding-left:22px}pre{white-space:pre-wrap;overflow-wrap:anywhere;font:inherit}section,details,article{scroll-margin-top:90px}
.lesson-layout{display:grid;grid-template-columns:210px minmax(0,1fr);margin:-34px -32px -70px;min-height:calc(100vh - 90px)}.lesson-layout.outline-closed{grid-template-columns:0 minmax(0,1fr)}.lesson-rail{background:var(--sidebar);position:relative;z-index:30;min-width:0;border-right:1px solid var(--line)}.rail-sticky{position:sticky;top:20px;padding-top:22px}.lesson-outline{padding:10px 16px 24px}.lesson-outline a{display:block;padding:10px 12px;margin:5px 0;font-size:13px;color:var(--ink);border-radius:8px;overflow-wrap:anywhere}.lesson-outline a.active,.lesson-outline a:hover{background:var(--paper);color:var(--primary);text-decoration:none}.outline-toggle{position:absolute;right:-16px;top:24px;width:32px;min-height:44px;padding:0;font-size:28px;line-height:1;border-radius:14px;background:var(--paper);z-index:35}.outline-closed .outline-toggle{right:-32px}.lesson-content{min-width:0;padding:32px 32px 50px 42px}.lesson-tabs{display:flex;gap:5px;flex-wrap:wrap;position:sticky;top:0;z-index:20;background:var(--bg);padding:12px 0 8px;border-bottom:1px solid var(--line);margin:25px 0 30px;box-shadow:0 6px 0 var(--bg)}.lesson-tabs a{display:inline-flex;align-items:center;min-height:44px;padding:8px 15px;border-bottom:3px solid transparent;border-radius:7px 7px 0 0;font-size:14px;color:var(--muted)}.lesson-tabs a.active,.lesson-tabs a:hover{background:var(--soft);border-bottom-color:var(--primary);color:var(--primary);text-decoration:none}.lesson-section{padding:16px 0 26px;border-bottom:1px solid var(--line);margin-bottom:22px}.lesson-section h2{margin-top:0}.reading{max-width:720px;margin:0 auto;min-width:0}.reading p{line-height:2;overflow-wrap:anywhere}.visual-reading{display:grid;grid-template-columns:minmax(250px,1.1fr) minmax(230px,1fr);align-items:start;gap:28px}.visual-reading .reading{width:100%}.lesson-figure{background:var(--paper);padding:22px;border-radius:12px;margin:0;color:var(--ink);min-width:0}.lesson-figure svg{width:100%;height:auto;display:block;font-family:"Segoe UI","Microsoft YaHei",sans-serif}.figure-label{font-size:13px;font-weight:600;color:var(--primary)}figcaption{font-size:13px;color:var(--muted);line-height:1.8;margin:15px 0}.figure-zoom{min-height:38px;font-size:13px;padding:5px 12px}.figure-dialog{width:min(92vw,1000px);max-height:90vh;overflow:auto;background:var(--paper);color:var(--ink);border:1px solid var(--line);border-radius:14px;padding:25px}.figure-dialog::backdrop{background:#121323cc}.figure-dialog [data-zoom-close]{display:block;margin-left:auto}.figure-dialog svg{width:100%;max-height:65vh}.figure-dialog .lesson-figure{border:0}.lesson-footer{display:flex;justify-content:space-between;align-items:center;gap:20px;flex-wrap:wrap;border-top:1px solid var(--line);padding-top:24px;margin-top:30px;font-size:14px}.next-lesson{margin-left:auto}.callout,.answer-feedback{background:var(--callout);padding:21px 24px;border-radius:10px;margin:25px 0}.callout h3,.feedback-title{color:#c3caff}.callout p:last-child{margin-bottom:0}
.filters{display:flex;align-items:end;gap:14px;flex-wrap:wrap;margin:25px 0}.filters label{display:grid;gap:6px;font-size:13px}.filters select{max-width:260px}input,select,textarea{background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:7px;padding:10px 12px;max-width:100%}input[type=radio],input[type=checkbox]{accent-color:var(--primary);padding:0;width:18px;height:18px;flex:none}textarea{width:100%;min-height:160px;resize:vertical;line-height:1.8}.signin{max-width:430px;margin:5vh auto}.signin input{display:block;width:100%;margin-top:6px}.exercise-card{max-width:940px;background:var(--paper);border:1px solid var(--line);border-radius:12px;padding:26px 28px;margin:23px 0;scroll-margin-top:90px}.exercise-meta{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin-bottom:15px}.exercise-prompt{font-size:18px;line-height:1.9;white-space:pre-line}.response{margin-top:22px;max-width:760px}.response>p>label{display:block;margin-bottom:7px}.response input[type=text]{width:230px}.response label:has(input[type=radio]){display:flex;gap:12px;align-items:center;padding:10px 12px;border-radius:7px;cursor:pointer}.response label:has(input[type=radio]):hover{background:var(--soft)}.response div[id$=answer]>div{margin:6px 0}.response label:has(input:checked){background:var(--soft)}.response button{margin-top:12px}.errorlist,.request-error{color:#f3b8d4}.request-error{margin-top:15px}.attempt-history{background:transparent;font-size:13px;padding:10px 15px}.answer-feedback{margin-bottom:15px}.answer-feedback pre{background:var(--bg);padding:14px;border-radius:6px}.answer-feedback h3{margin-top:16px}.answer-feedback h3:first-child{margin-top:0}.exercise{padding:20px 0;border-bottom:1px solid var(--line)}.empty-state{border:1px dashed var(--line);border-radius:10px;padding:25px;margin:22px 0;color:var(--muted)}.empty-state h3{color:var(--ink)}
.evidence-chart{max-width:800px;background:var(--paper);padding:24px;border-radius:12px;margin:22px 0}.chart-legend{display:flex;gap:24px;flex-wrap:wrap;font-size:13px;margin-bottom:28px}.swatch{width:10px;height:10px;display:inline-block;border-radius:50%;margin-right:7px}.swatch.correct,.count-segment.correct{background:var(--correct)}.swatch.wrong,.count-segment.wrong{background:var(--wrong)}.swatch.pending,.count-segment.pending{background:var(--pending)}.evidence-row{display:grid;grid-template-columns:95px minmax(0,1fr);gap:18px;margin:22px 0;align-items:center}.dimension-label{font-size:14px}.count-track{background:var(--bg);height:34px;display:flex;border-radius:5px;overflow:hidden}.count-segment{display:flex;align-items:center;justify-content:center;color:#f6f3ff;font-size:13px;font-weight:600;font-variant-numeric:tabular-nums;min-width:0}.chart-axis{margin:0 0 20px 113px;display:flex;justify-content:space-between;font-size:12px;color:var(--muted)}.pages{display:flex;gap:18px;align-items:center;flex-wrap:wrap;margin-top:25px}
@media(max-width:1050px){.visual-reading{grid-template-columns:1fr}.lesson-figure{max-width:630px;width:100%;margin:auto}.lesson-outline a{font-size:12px}.lesson-layout{grid-template-columns:180px minmax(0,1fr)}body>header>div{gap:20px}body>header nav{gap:15px}}
@media(max-width:760px){body>header>div{padding:16px 20px;gap:16px}.brand{font-size:18px}body>header nav{order:3;width:100%;font-size:13px;gap:17px}body>header form{margin-left:auto}.site-main{padding:25px 18px 45px}.lesson-layout,.lesson-layout.outline-closed{grid-template-columns:0 minmax(0,1fr);margin:-25px -18px -45px}.lesson-rail{width:195px;background:transparent;border:0;pointer-events:none}.rail-sticky{background:var(--sidebar);pointer-events:auto;border-right:1px solid var(--line)}.outline-closed .lesson-rail{width:0}.lesson-content{padding:25px 18px 45px 36px}.lesson-tabs{gap:0}.lesson-tabs a{padding:8px 10px;font-size:13px}.exercise-card{padding:21px 18px}.evidence-chart{padding:20px 15px}.evidence-row{grid-template-columns:70px minmax(0,1fr);gap:8px}.dimension-label{font-size:12px}.chart-axis{margin-left:78px}.lesson-figure{padding:15px}dl{display:block}dd{margin:3px 0 12px}input,select,textarea{font-size:16px}summary small{display:block;margin:5px 0}.cards{grid-template-columns:1fr}.filters select{max-width:100%}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}