:root{--bg:#f6f5f0;--paper:#fffefa;--ink:#273b35;--muted:#748079;--green:#375c4c;--lime:#e7edc9;--line:#e5e7dd;--orange:#b77951;--purple:#74628a;--shadow:0 12px 36px #263f3106}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif}button,input,select,textarea{font:inherit}button,a,input,select,textarea{ -webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}button:focus-visible,a:focus-visible{outline:3px solid #b7ca81;outline-offset:4px}a{color:inherit;text-decoration:none}.shell{display:grid;grid-template-columns:230px 1fr;min-height:100vh}.sidebar{position:sticky;top:0;height:100vh;padding:35px 24px;display:flex;flex-direction:column;border-right:1px solid var(--line);background:#fbfbf6}.logo{display:flex;align-items:center;gap:12px;font-size:22px;font-weight:750;letter-spacing:-1px}.logo-icon{height:38px;width:38px;display:grid;place-items:center;background:var(--green);color:white;border-radius:12px;font-family:Georgia,serif}.logo small{display:block;font-size:10px;letter-spacing:2px;font-weight:500;color:var(--muted)}.side-label{font-size:10px;letter-spacing:2px;color:#929b8e;margin:45px 14px 12px}.nav{display:grid;gap:8px}.nav button{border:0;background:none;color:#718073;text-align:left;padding:12px 16px;border-radius:10px;display:flex;gap:12px;align-items:center}.nav button.active{background:#e8eddf;color:var(--green);font-weight:700}.nav svg{width:19px;height:19px}.side-bottom{margin-top:auto;font-size:12px;color:var(--muted);padding:18px 12px;border-top:1px solid var(--line)}main{max-width:1320px;width:100%;margin:auto;padding:30px 48px 60px}.topbar{display:flex;align-items:center;justify-content:space-between;margin-bottom:30px;color:var(--muted);font-size:12px}.avatar{display:flex;align-items:center;gap:10px}.avatar span{background:#ece4d9;color:#8c765c;border-radius:50%;width:30px;height:30px;display:grid;place-items:center;font-weight:700}.eyebrow{font-size:11px;text-transform:uppercase;letter-spacing:2px;color:var(--muted);margin:0 0 10px}.heading{display:flex;justify-content:space-between;align-items:end;gap:15px;margin-bottom:25px}h1{font-size:32px;line-height:1.35;letter-spacing:-1px;margin:0 0 10px}h2{font-size:20px;margin:0}h3{font-size:16px;margin:0 0 8px}p{margin:0 0 12px}.muted{color:var(--muted);font-size:13px}.hero{padding:32px 36px;background:var(--green);border-radius:20px;color:#fbfcf4;display:grid;grid-template-columns:1fr 190px;gap:20px;overflow:hidden;position:relative;margin-bottom:23px}.hero .eyebrow,.hero .muted{color:#ccd8c8}.hero h2{font-size:28px;margin:10px 0 13px;line-height:1.5}.hero p{font-size:13px;max-width:520px}.hero-art{display:flex;align-items:center;justify-content:center;position:relative;min-height:150px}.orbit{border:1px solid #bbcfaa55;border-radius:50%;height:160px;width:160px;display:grid;place-items:center;transform:rotate(-12deg)}.orbit:before{content:'';height:115px;width:115px;border:1px dashed #bbcfaa77;border-radius:50%;position:absolute}.orbit b{font:70px/1 Georgia,serif;color:var(--lime)}.orbit span{position:absolute;right:3px;top:18px;font-size:25px;color:var(--lime)}.btn{background:var(--green);color:white;border:0;border-radius:9px;padding:11px 18px;font-size:13px;font-weight:650;display:inline-flex;align-items:center;gap:10px;justify-content:center}.btn.light{background:var(--lime);color:var(--ink)}.btn.secondary{background:var(--paper);border:1px solid var(--line);color:var(--green)}.btn.text{background:transparent;color:var(--muted);padding:8px}.btn:disabled{opacity:.45;cursor:default}.actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:22px 0 30px}.stat{background:var(--paper);border:1px solid var(--line);padding:20px 23px;border-radius:13px}.stat strong{font:32px/1.3 Georgia,serif;display:block;margin:8px 0}.stat small{color:var(--muted);font-size:12px}.section-title{display:flex;justify-content:space-between;align-items:center;gap:12px;margin:28px 0 15px}.section-title small{font-size:12px;color:var(--muted)}.grid2{display:grid;grid-template-columns:1fr 1fr;gap:20px}.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.card{background:var(--paper);border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:var(--shadow)}.subject-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px}.subject-icon{width:43px;height:43px;border-radius:12px;background:#edf0df;color:var(--green);display:grid;place-items:center;font:22px Georgia,serif}.subject-icon.math{background:#f2e9df;color:#a47a55}.tag{font-size:11px;border-radius:6px;background:#eef0e6;padding:4px 8px;color:#66715f;display:inline-block}.tag.purple{background:#efeaf4;color:var(--purple)}.tag.orange{background:#f6eadf;color:#9c6e4a}.subject-card h3{font-size:23px}.progress{height:5px;background:#eceee5;border-radius:10px;margin:18px 0 8px;overflow:hidden}.progress i{display:block;height:100%;background:#99ad76;border-radius:10px}.row{display:flex;justify-content:space-between;align-items:center;gap:12px}.divider{height:1px;background:var(--line);margin:20px 0}.notice{border-left:3px solid #bdc999;padding:12px 17px;background:#edf0e3;font-size:12px;color:#65705d;border-radius:0 8px 8px 0;margin:20px 0}.empty{text-align:center;padding:30px 12px;color:var(--muted)}.empty b{display:block;color:var(--ink);font-size:16px;margin:8px 0}.roadmap{display:flex;gap:15px;align-items:center;padding:15px 0;border-bottom:1px solid var(--line)}.step{width:28px;height:28px;flex-shrink:0;background:#e8eddc;border-radius:50%;display:grid;place-items:center;font-size:12px}.roadmap:last-child{border-bottom:0}.mini{font-size:12px;color:var(--muted)}.vocab-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.word{border:1px solid var(--line);border-radius:12px;padding:18px;background:var(--paper);text-align:left;color:var(--ink);min-height:150px;position:relative}.word strong{font:24px Georgia,serif;display:block;margin:0 0 8px}.word.revealed{background:#eff2e6}.word .example{font-size:12px;color:var(--muted);margin-top:10px}.word .hidden-meaning{color:#87927b;font-size:12px}.tabs{display:flex;gap:7px;flex-wrap:wrap;margin:20px 0}.tabs button{background:none;border:1px solid var(--line);border-radius:20px;padding:7px 15px;color:var(--muted);font-size:13px}.tabs button.active{background:var(--green);color:white;border-color:var(--green)}.lesson{margin-bottom:15px}.lesson summary{cursor:pointer;font-weight:650;list-style:none;display:flex;justify-content:space-between;gap:12px}.lesson summary:after{content:'+';color:var(--muted)}.lesson[open] summary:after{content:'−'}.lesson .body{padding-top:18px;font-size:14px}.example-box{background:#f2f3eb;border-radius:9px;padding:14px 17px;margin:14px 0;white-space:pre-line}.error-card{padding:22px 24px;margin-bottom:12px}.error-card .wrong{color:#ad6b55;text-decoration:line-through}.error-card .right{color:var(--green);font-weight:650}.error-equation{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:12px;margin:15px 0;padding:15px;background:#f7f7f1;border-radius:8px}.error-equation small{display:block;color:var(--muted);font-size:11px;margin-bottom:5px}.quiz-shell{max-width:760px;margin:0 auto}.quiz-shell h1{font-size:25px}.quiz-top{margin-bottom:23px}.question{font-size:21px;line-height:1.8;margin:22px 0;white-space:pre-line}.options{display:grid;gap:11px}.option{background:var(--paper);border:1px solid var(--line);color:var(--ink);padding:15px 18px;border-radius:10px;text-align:left;display:flex;gap:15px;align-items:center}.option.selected{background:#eaf0df;border-color:#78926a}.option.correct{background:#e6efdf;border-color:#729760}.option.incorrect{background:#faeee5;border-color:#c6937d}.option:disabled{cursor:default;opacity:1}.option b{display:grid;place-items:center;border:1px solid #dce1d3;border-radius:6px;width:26px;height:26px;font-size:12px;flex-shrink:0}.feedback{background:#edf2e6;padding:20px;border-radius:12px;margin-top:20px;white-space:pre-line}.feedback.bad{background:#f7eee5}.hint{background:#f8f0df;padding:15px;border-radius:10px;margin:15px 0;font-size:13px}.quiz-footer{display:flex;justify-content:space-between;align-items:center;margin-top:23px;gap:10px}.result-score{font:64px Georgia,serif;letter-spacing:-2px;margin:20px 0;color:var(--green)}.skill-row{display:grid;grid-template-columns:1fr auto;gap:12px;padding:18px 0;border-bottom:1px solid var(--line)}.skill-row:last-child{border-bottom:0}.skill-row p{font-size:12px;color:var(--muted);margin:5px 0 0}.status{font-size:11px;padding:4px 9px;border-radius:6px;background:#eeefe7;color:#7f8777;height:max-content}.status.learning{background:#f7e9d9;color:#9b7752}.status.good{background:#e6efd9;color:#65804d}.log{padding:15px 0;border-bottom:1px solid var(--line)}.log:last-child{border-bottom:0}.bar-row{display:grid;grid-template-columns:70px 1fr 34px;gap:14px;align-items:center;font-size:12px;margin:15px 0}.bar-row .progress{margin:0;height:9px}form{display:grid;gap:15px}label{font-size:13px;display:grid;gap:6px}input,select,textarea{width:100%;border:1px solid #dce1d4;background:white;border-radius:8px;padding:11px 13px;color:var(--ink)}textarea{min-height:90px;resize:vertical}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.inline-label{display:flex;align-items:center;gap:8px;font-size:12px}.inline-label input{width:auto}.footer{font-size:11px;color:#87917f;margin-top:35px;display:flex;gap:15px;justify-content:space-between}.legacy{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:white}.legacy iframe{display:block;width:100%;height:780px;border:0}.back{font-size:13px;color:var(--muted);background:none;border:0;padding:0;margin-bottom:22px}#toast{position:fixed;bottom:25px;left:50%;transform:translateX(-50%);background:var(--ink);color:white;border-radius:10px;padding:12px 20px;font-size:13px;max-width:90vw;z-index:100;display:none}.mobile-brand{display:none}.metric-note{font-size:11px;color:var(--muted)}.new-badge{color:#b8cb9a;margin-right:8px}.last-line{margin-top:25px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}@media(min-width:1500px){main{padding-left:60px;padding-right:60px}}@media(max-width:1050px){.shell{grid-template-columns:185px 1fr}.sidebar{padding:30px 14px}main{padding:25px}.hero{grid-template-columns:1fr 130px;padding:28px}.orbit{height:125px;width:125px}.orbit:before{height:90px;width:90px}.grid3{grid-template-columns:1fr 1fr}.vocab-grid{grid-template-columns:1fr 1fr}}@media(max-width:700px){.shell{display:block}.sidebar{height:65px;position:fixed;top:auto;bottom:0;left:0;width:100%;z-index:30;border-right:0;border-top:1px solid var(--line);padding:6px 3px;background:#fbfbf6f5;backdrop-filter:blur(15px)}.sidebar>.logo,.side-label,.side-bottom{display:none}.nav{display:flex;justify-content:space-around;gap:0}.nav button{display:grid;justify-items:center;gap:2px;padding:3px 8px;font-size:10px;border-radius:8px}.nav svg{width:20px;height:20px}.nav button.active{background:transparent}.mobile-brand{display:flex;font-size:17px;gap:8px;align-items:center;color:var(--green);font-weight:700}.mobile-brand .logo-icon{width:27px;height:27px;border-radius:8px;font-size:17px}.topbar{margin-bottom:26px}.date{display:none}main{padding:22px 18px 95px}h1{font-size:27px}.heading{display:block}.heading>.btn{margin-top:8px}.hero{grid-template-columns:1fr;padding:25px;border-radius:16px}.hero-art{display:none}.hero h2{font-size:24px}.stats{gap:8px;margin:18px 0 25px}.stat{padding:13px 11px;border-radius:11px}.stat strong{font-size:27px}.stat small,.stat .muted{font-size:10px}.grid2,.grid3{grid-template-columns:1fr;gap:14px}.card{padding:20px}.vocab-grid{gap:9px}.word{padding:15px;min-height:145px}.word strong{font-size:22px}.section-title h2{font-size:18px}.section-title small{font-size:10px}.footer{display:block}.footer span{display:block;margin:5px 0}.form-grid{grid-template-columns:1fr}.question{font-size:18px}.quiz-footer{flex-wrap:wrap}.error-equation{grid-template-columns:1fr;gap:5px}.error-equation>span{display:none}.legacy iframe{height:740px}.skill-row{grid-template-columns:1fr auto}.subject-card h3{font-size:22px}#toast{bottom:85px}.topbar .avatar{font-size:11px}.notice{font-size:11px}}
/* Knowledge connection maps */
.map-intro{display:flex;gap:20px;align-items:center;justify-content:space-between;margin:30px 0 18px}.map-intro h2{font-size:26px;margin:8px 0}.map-intro p{margin-bottom:0}.map-intro>.tag{white-space:nowrap}.map-toolbar{display:flex;justify-content:space-between;align-items:center;gap:15px;margin-bottom:16px}.map-legend{display:flex;gap:18px;flex-wrap:wrap;font-size:12px}.map-legend span{display:flex;align-items:center;gap:7px}.map-legend i,.relation-dot{display:inline-block;width:9px;height:9px;border-radius:50%}.map-legend .before,.relation-dot.before{background:#497fbd}.map-legend .current{background:#375c4c}.map-legend .after,.relation-dot.after{background:#bd7c3e}.knowledge-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:18px;align-items:start}.map-scroll{overflow:auto;max-height:830px;border:1px solid var(--line);border-radius:16px;background:#fbfcf8;overscroll-behavior:contain}.knowledge-canvas{position:relative;width:1115px;isolation:isolate;background-image:radial-gradient(#d9e0d4 .8px,transparent .8px);background-size:16px 16px}.map-root{position:absolute;left:25px;top:18px;font-size:22px;font-weight:750;display:flex;gap:16px;align-items:center}.map-root small{font-size:11px;font-weight:400;color:var(--muted)}.map-group{position:absolute;top:63px;width:190px;padding-left:12px;border-left:3px solid #bcc8a8;display:grid;line-height:1.6}.map-group small{font-size:10px;color:var(--muted)}.map-group b{font-size:15px}.map-wires{position:absolute;inset:0;z-index:-1;overflow:visible;pointer-events:none}.map-edge{fill:none;stroke-width:1.2;stroke:#abb6a6;opacity:.19}.map-edge.before{stroke:#497fbd;opacity:1;stroke-width:2.5}.map-edge.after{stroke:#bd7c3e;opacity:1;stroke-width:2.5}.all-lines .map-edge.other{opacity:.6}.arrow-before{fill:#497fbd}.arrow-after{fill:#bd7c3e}.arrow-other{fill:#abb6a6}.map-node{position:absolute;width:190px;min-height:77px;padding:11px 12px;border:1px solid #dbe2d5;border-radius:11px;background:#fffefa;color:var(--ink);text-align:left;box-shadow:0 3px 12px #344b3310;transition:border-color .15s,box-shadow .15s}.map-node strong{font-size:13px;display:block;margin-bottom:6px;line-height:1.4}.map-node .status{font-size:10px;padding:2px 7px;display:inline-block}.map-node.before{border:2px solid #497fbd;background:#f2f7fd}.map-node.after{border:2px solid #bd7c3e;background:#fff7ed}.map-node.current{border:2px solid var(--green);background:#e8eddf;box-shadow:0 0 0 4px #375c4c13}.map-node:hover{box-shadow:0 4px 16px #344b3326}.map-detail{position:sticky;top:20px;padding:22px;max-height:calc(100vh - 40px);overflow:auto}.map-detail h3{font-size:21px;line-height:1.4;margin:8px 0 12px}.map-detail .example-box{font-size:13px;overflow-wrap:anywhere}.map-detail hr{border:0;border-top:1px solid var(--line);margin:24px 0}.map-detail h4{font-size:13px;margin:20px 0 10px}.map-detail h4 .relation-dot{margin-right:6px}.map-actions{display:grid;gap:8px}.map-related{display:flex;flex-wrap:wrap;gap:7px}.map-link{border:1px solid #d6e0ed;border-radius:7px;background:#f2f7fd;color:#37669d;font-size:12px;padding:6px 9px;text-align:left}.map-link.after{background:#fff7ed;border-color:#ecd6be;color:#9b642f}.status.neutral{color:#7b8177;background:#edf0e9}.map-scroll:focus-visible{outline:3px solid #b7ca81;outline-offset:3px}
@media(min-width:1700px){.map-scroll{max-height:none}}@media(max-width:1100px){.knowledge-layout{grid-template-columns:minmax(0,1fr)}.map-detail{position:static;max-height:none;display:block}.map-scroll{max-height:650px}}@media(max-width:600px){.map-intro{display:block}.map-intro>.tag{display:inline-block;margin-top:12px}.map-intro h2{font-size:23px}.map-toolbar{align-items:flex-start;flex-direction:column}.map-legend{gap:11px;font-size:11px}.map-scroll{max-height:530px}.map-detail{padding:20px}.map-root{font-size:20px}}
.knowledge-canvas{width:1015px}.map-node,.map-group{width:170px}.map-selection{display:flex;flex-wrap:wrap;gap:8px 20px;align-items:center;padding:13px 16px;margin-bottom:15px;background:#e8eddf;border-radius:10px;font-size:12px}.map-selection span{color:var(--muted)}.map-detail-jump{border:0;background:none;color:var(--green);padding:0;text-decoration:underline;text-underline-offset:3px}.map-detail{scroll-margin-top:20px}
@media(max-width:1699px){.knowledge-layout{grid-template-columns:minmax(0,1fr)}.map-scroll{max-height:750px}.map-detail{position:static;max-height:none}.map-detail>p,.map-detail>.example-box{max-width:850px}.map-actions{display:flex;flex-wrap:wrap}.map-detail .map-related{gap:10px}}@media(max-width:600px){.map-scroll{max-height:530px}.map-selection{gap:7px}.map-selection span{width:100%}}
/* Radial mind map: hierarchy is visible before any node is selected. */
.map-toolbar{flex-wrap:wrap;justify-content:flex-start}.map-legend{margin-right:auto}.mind-scroll{max-height:780px;min-height:320px;cursor:grab;touch-action:pan-x pan-y;background:#fffefa}.mind-scroll.dragging{cursor:grabbing;user-select:none}.mind-stage{position:relative;margin:auto}.mind-canvas{position:relative;width:1800px;height:1400px;transform-origin:top left;background:radial-gradient(ellipse at center,#eff3e6 0,transparent 46%)}.mind-wires{position:absolute;inset:0;pointer-events:none}.mind-trunk{fill:none;stroke-width:5;opacity:.75}.mind-twig{fill:none;stroke-width:2;opacity:.5}.mind-line-label{font-size:13px;fill:#819078}.mind-center{position:absolute;left:820px;top:622px;width:160px;height:76px;border-radius:40px;background:#375c4c;color:white;box-shadow:0 6px 25px #375c4c25;display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:28px;font-weight:750}.mind-center small{font-size:12px;letter-spacing:2px;font-weight:400;opacity:.75}.mind-branch{position:absolute;width:170px;min-height:56px;padding:12px 8px;text-align:center;border-radius:30px;color:var(--branch);border:2px solid var(--branch);background:#fffefa;font-size:21px;font-weight:700}.map-node.mind-node{width:230px;height:60px;min-height:60px;border:0;border-bottom:2px solid var(--branch);border-radius:8px 8px 0 0;box-shadow:none;padding:6px 10px;background:#fffefa}.mind-node strong{font-size:16px;margin-bottom:1px;font-weight:550;white-space:nowrap}.mind-node .status{font-size:10px;background:transparent;padding:0}.mind-node.current{background:#e4edda;outline:3px solid #375c4c}.mind-node.before{background:#edf5ff;outline:2px solid #497fbd}.mind-node.after{background:#fff2e3;outline:2px solid #bd7c3e}.mind-cross .map-edge{stroke-dasharray:7 6;stroke-width:2;opacity:.9;fill:none}.mind-cross.other .map-edge{stroke-width:1;opacity:.2}.mind-edge-label{font-size:13px;paint-order:stroke;stroke:#fffefa;stroke-width:7px;stroke-linejoin:round;fill:#497fbd;font-weight:600}.mind-edge-label.after{fill:#a5682e}.knowledge-layout{grid-template-columns:minmax(0,1fr)}.map-detail{position:static;max-height:none}@media(max-width:600px){.mind-scroll{max-height:580px;min-height:250px}.map-toolbar .btn{font-size:12px;padding:7px 10px}.map-toolbar .map-legend{width:100%}}