:root{color-scheme:light;--bg:#f8f5ef;--card:#fffdf8;--text:#27382f;--muted:#67756c;--line:#d8ded5;--accent:#365744;--soft:#edf0e9;--button:#fffdf8}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font:15px/1.9 system-ui,-apple-system,"PingFang SC",sans-serif}body.dark{color-scheme:dark;--bg:#111b18;--card:#192720;--text:#edf0e7;--muted:#b2c1b7;--line:#3d5145;--accent:#c1d5b5;--soft:#26382c;--button:#18271d}main{max-width:1320px;margin:auto;padding:28px 32px}header{display:flex;align-items:flex-start;justify-content:space-between;gap:20px;margin-bottom:26px}h1,h2,h3{font-family:"Songti SC","STSong",serif;line-height:1.5;font-weight:600}h1{font-size:40px;margin:0}h2{font-size:29px;margin:8px 0 18px}h3{font-size:22px;margin:12px 0}p{overflow-wrap:anywhere;margin:10px 0 16px}button,input,select{color:var(--text);background:var(--card);font:14px/1.5 system-ui,-apple-system,"PingFang SC",sans-serif;min-height:44px;border:1px solid var(--line);border-radius:5px;padding:10px 13px;max-width:100%}button{cursor:pointer}button:hover{background:var(--soft);border-color:var(--accent)}button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible,a:focus-visible{outline:2px solid var(--accent);outline-offset:3px}.eyebrow{font-size:12px;color:var(--accent);margin:0 0 6px;letter-spacing:1px}.lead{color:var(--muted);margin:8px 0 0}.tabs{display:flex;border-bottom:1px solid var(--line);margin-bottom:30px;gap:24px}.tabs button{border:0;border-bottom:2px solid transparent;background:transparent;border-radius:0;padding:12px 6px;font-size:15px}.tabs button[aria-selected=true]{border-color:var(--accent);font-weight:650;color:var(--accent)}.opening{border-left:3px solid var(--accent);padding:22px 32px;margin:10px 0 34px;background:var(--soft)}.opening>p{max-width:850px}.primary{background:var(--accent);color:var(--button);border-color:var(--accent);margin-top:10px}.primary:hover{background:var(--accent);filter:brightness(.95)}.lessons{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:30px}.lessons article{border-top:1px solid var(--line);padding:22px 0}.index{font:24px "Songti SC",serif;color:var(--accent)}.lessons p{font-size:14px}.practice{border-top:1px solid var(--line);padding:24px 0;margin-top:20px}.practice p{max-width:940px}.muted{color:var(--muted);font-size:13px}.line-example{display:grid;grid-template-columns:70px 1fr;align-items:center;gap:15px;font-size:13px}.yao{display:flex;height:7px;gap:16%;width:100%}.yao i{display:block;height:100%;background:currentColor;flex:1}.diagram{display:flex;flex-direction:column;gap:7px;color:var(--accent);width:72px;flex-shrink:0}.trigram-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:20px;margin-top:25px}.trigram-grid article{border:1px solid var(--line);background:var(--card);padding:24px;border-radius:6px}.trigram-grid button{font-size:12px;padding:8px 10px}.atlas-layout{display:grid;grid-template-columns:minmax(0,1fr) 370px;gap:28px;align-items:start}.catalog{min-width:0}label{display:flex;flex-direction:column;gap:7px;font-size:13px}input,select{width:100%;min-width:0}.filters{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:16px 0}.list-caption{display:flex;align-items:center;justify-content:space-between;margin:12px 0;font-size:13px}.list-caption p{margin:0}.list-caption button{font-size:12px;min-height:36px;padding:7px 10px}.hex-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px}.hex-button{display:flex;flex-direction:column;align-items:center;padding:16px 5px;gap:8px;border-radius:6px}.hex-button strong{font-size:16px;font-weight:600}.hex-button small{font-size:11px;color:var(--muted)}.hex-button .diagram{width:44px;gap:4px;margin-bottom:4px}.hex-button .yao{height:4px}.hex-button[aria-pressed=true]{border-color:var(--accent);background:var(--soft)}.empty{grid-column:1/-1}#hex-detail{background:var(--card);padding:25px;border:1px solid var(--line);border-radius:6px;scroll-margin-top:16px}#hex-detail>h3{font-size:34px;margin:2px 0}.line-controls{display:flex;flex-direction:column;gap:8px;margin:22px 0}.line-control{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:46px;padding:10px}.line-control .diagram{width:96px}.line-control small{font-size:10px;color:var(--muted)}.line-control[aria-pressed=true]{background:var(--soft);border-color:var(--accent)}.change-result{border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:16px 0;margin:12px 0}.change-result .diagram{margin:14px 0}.change-result p{margin:8px 0}.reading-list{display:grid;grid-template-columns:1fr 1fr;gap:24px}.reading-list article{border-top:1px solid var(--line);padding:20px 0}.reading-list b{font-size:13px;color:var(--accent)}.note{border-top:1px solid var(--line);padding:18px 0}.note summary{cursor:pointer;font-size:15px;font-weight:600}.note p,.note li{font-size:13px}.note[open] summary{margin-bottom:12px}a{color:var(--accent)}footer{margin-top:35px}footer>p{font-size:12px;color:var(--muted);text-align:center;margin-top:25px}[hidden]{display:none!important}@media(max-width:1000px){.atlas-layout{grid-template-columns:minmax(0,1fr) 320px;gap:20px}.hex-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.trigram-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.lessons{gap:20px}#hex-detail{padding:18px}}@media(max-width:800px){main{padding:22px 20px}.lessons,.atlas-layout{grid-template-columns:1fr}.hex-grid{grid-template-columns:repeat(4,minmax(0,1fr));max-height:510px;overflow:auto;padding:4px}.line-controls{max-width:380px}.line-control .diagram{width:120px}.opening{padding:20px 24px}}@media(max-width:480px){main{padding:20px 14px}h1{font-size:34px}h2{font-size:26px}.lead{font-size:14px}.tabs{gap:0;justify-content:space-between}.tabs button{font-size:13px;padding:12px 6px}.opening{padding:18px}.opening h2{font-size:25px}.trigram-grid{gap:12px}.trigram-grid article{padding:18px 12px}.hex-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.reading-list{grid-template-columns:1fr}.trigram-grid h3{font-size:21px}.trigram-grid .muted{font-size:11px}.trigram-grid button{font-size:11px}#hex-detail{padding:18px}.line-control .diagram{width:105px}.filters{gap:12px}}