:root{--ink:#193632;--muted:#64736e;--line:#dce3dc;--green:#236454;--paper:#fafbf7;--soft:#eef3eb;--amber:#82551b}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 -apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft Yahei",sans-serif}.demo{background:#e9eee6;text-align:center;font-size:12px;padding:7px 16px;color:#506248}header{height:86px;display:flex;align-items:center;justify-content:space-between;padding:0 5%;border-bottom:1px solid var(--line);background:#fff}.brand{display:flex;gap:13px;align-items:center;font-size:26px;font-weight:650;color:var(--ink);text-decoration:none;letter-spacing:-1px}.brand small{font-size:13px;letter-spacing:2px;font-weight:400;margin-left:9px}.symbol{display:grid;place-items:center;background:var(--green);color:white;width:39px;height:43px;border-radius:11px 11px 11px 2px;font:italic 28px Georgia}.profile{font-size:12px;color:var(--muted)}select{font:inherit;padding:10px;border:1px solid var(--line);border-radius:8px;color:var(--ink);background:white}.profile select{margin-left:8px;font-size:14px}.shell{display:grid;grid-template-columns:208px 1fr;max-width:1440px;margin:auto;min-height:calc(100vh - 120px)}aside{padding:36px 24px;border-right:1px solid var(--line)}.label,.eyebrow{font-size:12px;letter-spacing:2px;color:var(--muted);margin-bottom:16px}nav{display:grid;gap:8px}nav a{padding:11px 16px;text-decoration:none;color:var(--muted);border-radius:8px;font-size:15px}nav a.active{background:#e5eee2;color:var(--green);font-weight:600}.side-note{margin:55px 10px 0;font-size:12px;line-height:1.9;color:var(--muted)}main{padding:40px 5%;min-width:0;outline:none}h1{font-size:32px;letter-spacing:-.8px;font-weight:600;margin:4px 0 10px;line-height:1.35}h2{font-size:21px;font-weight:600;margin:0 0 16px}h3{font-size:16px;margin:0 0 9px}p{margin:10px 0 18px}.muted{color:var(--muted);font-size:14px}.head{margin-bottom:28px}.head p{max-width:680px}.hero{background:#e9efe3;border-radius:16px;padding:32px;margin:24px 0;display:grid;grid-template-columns:1.5fr 1fr;gap:25px}.hero h2{font-size:27px}.steps{border-left:1px solid #c6d2bf;padding-left:25px;font-size:14px;color:#486343;display:grid;align-content:center;gap:10px}.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.card{background:white;border:1px solid var(--line);border-radius:12px;padding:23px}.stat{font-size:32px;line-height:1.5}.foot{margin-top:26px;font-size:13px;color:var(--muted)}button,.button{display:inline-flex;align-items:center;justify-content:center;border:1px solid var(--line);background:white;border-radius:8px;padding:11px 19px;font:inherit;font-size:14px;text-decoration:none;cursor:pointer;color:var(--ink);min-height:44px}button:hover,.button:hover{border-color:var(--green);background:#f0f5ed}.primary{background:var(--green);color:white;border-color:var(--green)}.primary:hover{background:#184d40;color:white}button:disabled{opacity:.5;cursor:not-allowed}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #ca941b;outline-offset:3px}.fields{max-width:720px;display:grid;gap:22px}.field{display:grid;gap:7px}.field>span{font-size:14px;font-weight:600}.field input,.field select{width:100%;font-size:16px}input,textarea{font:inherit;border:1px solid var(--line);border-radius:8px;padding:12px;background:white;color:var(--ink);max-width:100%}textarea{width:100%;min-height:180px;resize:vertical}.hint{background:#f6f1e5;border-left:3px solid #ba9144;padding:14px 18px;font-size:14px;color:#70552e;margin:18px 0;border-radius:4px}.workspace{display:grid;grid-template-columns:190px minmax(0,1fr);gap:20px}.chapters{display:grid;gap:10px;align-content:start}.chapters button{text-align:left;justify-content:flex-start}.chapters .chosen{background:var(--soft);border-color:var(--green)}.reading{font-size:18px;line-height:1.95}.reading .example{background:var(--soft);padding:20px;border-radius:8px;font-family:Georgia,serif;font-size:22px;line-height:1.6}.divider{height:1px;background:var(--line);margin:24px 0}details{margin:18px 0}summary{cursor:pointer;font-size:14px;color:var(--green);padding:10px 0}.map-root{display:inline-block;background:var(--green);color:white;padding:12px 23px;border-radius:8px;margin-bottom:16px}.branch{border-left:2px solid #b9cbbb;padding:9px 17px;margin-left:20px;margin-bottom:10px;background:var(--soft);border-radius:0 8px 8px 0;overflow-wrap:anywhere}.split{display:grid;grid-template-columns:1fr 1fr;gap:22px}.options{display:grid;gap:12px;margin:22px 0}.option{display:flex;align-items:center;gap:12px;border:1px solid var(--line);padding:13px 18px;border-radius:8px;cursor:pointer}.option:has(input:checked){border-color:var(--green);background:var(--soft)}.option input{accent-color:var(--green);width:18px;height:18px}.result{padding:18px;background:var(--soft);border-radius:8px;margin-top:18px}.status{font-size:12px;background:var(--soft);padding:4px 9px;border-radius:5px;display:inline-block}.result-item{border-bottom:1px solid var(--line);padding:20px 0}.result-item:last-child{border:0}#notice:not(:empty){position:fixed;bottom:20px;left:50%;transform:translateX(-50%);background:#193632;color:white;padding:12px 22px;border-radius:8px;max-width:90%;z-index:10}a{color:var(--green)}@media(max-width:850px){header{padding:14px 20px;height:auto;gap:15px;flex-wrap:wrap}.shell{display:block}aside{padding:12px 16px;border-right:0;border-bottom:1px solid var(--line)}aside .label,.side-note{display:none}nav{display:flex;gap:5px;overflow:auto;white-space:nowrap}nav a{padding:8px 12px;font-size:14px}main{padding:26px 20px}h1{font-size:27px}.hero{grid-template-columns:1fr;padding:24px}.steps{border-left:0;border-top:1px solid #c6d2bf;padding:15px 0 0;gap:5px}.workspace,.split{grid-template-columns:1fr}.chapters{display:flex;flex-wrap:wrap}.chapters button{flex:1;min-width:105px}.grid{grid-template-columns:1fr}.reading{font-size:17px}.demo{font-size:11px}.brand small{margin-left:5px}.profile select{margin:0}.profile{display:flex;align-items:center;gap:10px}.card{padding:20px}.hero h2{font-size:23px}}

@media(max-width:500px){.chapters{display:grid;grid-template-columns:1fr}.chapters button{width:100%;padding:10px 14px}}
/* Student workspace v2: bright paper, blue navigation, subject accents. */
:root{--ink:#24334d;--muted:#657086;--line:#e2e7f1;--green:#345acf;--paper:#f7f9ff;--soft:#edf2ff;--subject-color:#9b4a12;--subject-bg:#fff5e4}
body{background:linear-gradient(160deg,#f1f5ff 0,#fafbff 40%,#fffaf4 100%);min-height:100vh}.demo{background:#edf1fc;color:#53627f}header{height:90px;padding:0 max(5%,calc((100vw - 1240px)/2));gap:22px;background:#ffffffed}.brand{margin-right:auto;letter-spacing:-.7px}.brand small{color:#687892}.symbol{background:#4268df;border-radius:13px;transform:rotate(-5deg);font-style:normal}.subject-picker{font-size:12px;color:var(--muted);display:flex;align-items:center;gap:8px}.subject-picker select{font-size:14px}.shell{display:block;max-width:1240px}.shell>aside{border:0;padding:15px 0 0}.shell>aside>.label,.side-note{display:none}nav{display:flex;justify-content:center;gap:12px;border-bottom:1px solid var(--line);padding-bottom:14px}nav a{font-size:15px;padding:9px 20px}nav a.active{background:#e8eeff;color:#2f51b5}main{padding:34px 28px 60px}h1{font-size:34px;font-weight:700;letter-spacing:-.6px}.head{margin-bottom:24px}.head p{max-width:none}.eyebrow{color:#5e72a0;font-size:12px}.shelf-heading{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px}.shelf-heading h2{margin:0;font-size:18px}.subject-grid{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:14px}.subject-card{background:#fff;display:flex;text-align:left;justify-content:flex-start;padding:18px 14px;gap:12px;position:relative;min-height:110px;border-radius:16px;border:1px solid var(--line);box-shadow:0 5px 14px #2c437005}.subject-card:hover{background:var(--subject-bg);border-color:var(--subject-color);transform:translateY(-2px)}.subject-card.selected{border:2px solid var(--subject-color);padding:17px 13px;background:var(--subject-bg)}.subject-card strong{font-size:18px;display:block;color:var(--ink)}.subject-card small{font-size:11px;display:block;line-height:1.8;color:#647086;margin-top:5px}.subject-mark{width:38px;height:44px;display:grid;place-items:center;flex-shrink:0;background:var(--subject-bg);color:var(--subject-color);font:600 23px Georgia,serif;border-radius:10px}.arrow{position:absolute;right:9px;top:4px;color:var(--subject-color);font-size:15px}.explore{margin:14px 0 24px}.explore summary{font-size:13px;width:fit-content;color:#52689c}.explore .subject-grid{margin-top:10px}.hero{background:#fff;border:1px solid #dee5f3;border-radius:20px;padding:30px 34px;box-shadow:0 10px 30px #345acf06;border-top:4px solid var(--subject-color)}.hero h2{font-size:26px}.steps{border-color:#e0e6f3;color:#455574;gap:13px}.steps b{display:inline-block;width:28px;height:28px;margin-right:7px;font-size:11px;line-height:28px;text-align:center;background:#eef2fd;color:#4662b2;border-radius:50%}.primary{background:#345acf;border-color:#345acf}.primary:hover{background:#294bb7}.progress-strip{display:flex;justify-content:space-between;gap:18px;flex-wrap:wrap;background:#edf2fe;padding:18px 23px;border-radius:12px;font-size:14px;color:#4e638b}.card{border-radius:16px;box-shadow:0 5px 20px #345acf04}.method-track{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-bottom:24px}.method-track>div{background:var(--subject-bg);border-radius:12px;padding:17px;color:var(--subject-color);font-size:14px}.method-track span{display:inline-block;margin-right:13px;font-weight:700}.example,.reading .example{background:var(--subject-bg);padding:20px;border-radius:12px;font:inherit;line-height:1.85}.reading{max-width:900px}.reading h2{margin-top:15px}.status{background:var(--subject-bg);color:var(--subject-color)}.map-root{background:#345acf}.branch{background:#edf2ff;border-color:#aabceb}.chapters .chosen{background:#edf2ff;border-color:#345acf}.hint{background:#fff7e8;color:#79561c}.result{background:#f0f4fe}.foot{font-size:12px}.option:has(input:checked){border-color:#345acf;background:#f0f4fe}
@media(max-width:1050px){.subject-grid{grid-template-columns:repeat(3,minmax(0,1fr))}header{padding:18px 26px}.shell>aside{padding:12px 20px 0}nav{gap:4px}nav a{padding:9px 13px}}
@media(max-width:650px){header{height:auto;display:grid;grid-template-columns:1fr 1fr;padding:18px 20px;gap:16px 10px}.brand{grid-column:1/-1;font-size:26px}.subject-picker,.profile{display:grid;gap:5px;align-items:start}.subject-picker select,.profile select{width:100%;font-size:13px;padding:9px;margin:0;min-width:0}.shell>aside{padding:8px 12px 0}nav{display:grid;grid-template-columns:repeat(3,1fr);gap:3px;padding-bottom:8px;overflow:visible}nav a{text-align:center;padding:8px 3px;font-size:13px}main{padding:26px 20px 40px}h1{font-size:27px}.subject-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.subject-card{padding:16px 10px;gap:8px;min-height:104px}.subject-card.selected{padding:15px 9px}.subject-card strong{font-size:17px}.subject-card small{font-size:10px}.subject-mark{width:28px;font-size:20px}.shelf-heading{align-items:start;gap:12px}.shelf-heading .muted{font-size:11px;text-align:right;max-width:135px}.hero{padding:24px 20px;gap:14px}.hero h2{font-size:23px}.method-track{grid-template-columns:1fr;gap:8px}.method-track>div{padding:12px 16px}.progress-strip{font-size:12px;padding:17px;display:grid;gap:10px}.steps{font-size:13px}.head p{font-size:14px}.reading{font-size:17px}}
.book-detail{display:grid;grid-template-columns:230px 1fr;gap:36px}.cover-button{padding:0;border:0;background:none;width:100%;height:auto}.cover-button img{display:block;width:100%;height:auto;border-radius:5px;box-shadow:3px 8px 18px #24334d20}.book-detail h2{margin-top:15px}.book-meta{display:grid;grid-template-columns:110px 1fr;gap:12px 18px;font-size:15px}.book-meta dt{color:var(--muted)}.book-meta dd{margin:0;overflow-wrap:anywhere}.book-meta dd span{display:block;font-size:12px}dialog{max-width:min(94vw,650px);max-height:94vh;border:1px solid var(--line);border-radius:14px;padding:14px}dialog::backdrop{background:#18283d99}dialog img{max-width:100%;max-height:78vh;object-fit:contain;display:block;margin:auto}dialog form{text-align:right;margin-bottom:8px}@media(max-width:650px){.book-detail{grid-template-columns:1fr;gap:16px}.cover-button{width:180px;display:block;margin:auto}.book-detail>div>p.muted{text-align:center}.book-meta{grid-template-columns:88px 1fr;gap:12px;font-size:14px}}
.book-filters{display:grid;grid-template-columns:1fr 1fr 1fr;gap:20px;margin-bottom:20px}.book-candidates{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:20px 0}.candidate{justify-content:flex-start;text-align:left;gap:20px;padding:18px;background:white;min-width:0}.candidate img{width:70px;height:98px;object-fit:contain}.candidate small{display:block;color:var(--muted);font-size:12px;margin-top:4px}.candidate.selected{border:2px solid #345acf;background:#f1f5ff}.candidate strong{font-size:17px}@media(max-width:650px){.book-filters{grid-template-columns:1fr 1fr;gap:14px}.book-filters>div{grid-column:1/-1}.book-candidates{grid-template-columns:1fr}.candidate{padding:14px}}