:root{--ink:#233e35;--green:#265c48;--muted:#738176;--line:#dfe5d8;--bg:#f6f8f1}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px system-ui,sans-serif}button,input,select{font:inherit}button{cursor:pointer}header{height:82px;background:#fcfdf9;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 max(5vw,24px)}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);font-size:24px;font-weight:750}.brand b{background:var(--green);color:white;border-radius:10px;padding:4px 11px;font-size:30px}.brand span{font-size:12px;border:1px solid var(--line);padding:4px 8px;border-radius:5px}select{padding:10px;background:transparent;color:var(--ink);border:1px solid var(--line);border-radius:8px}main{max-width:1220px;margin:auto;padding:40px 28px 0}.eyebrow{font-size:11px;letter-spacing:2px;color:#7c8a65;font-weight:750}h1{font-size:clamp(30px,4vw,46px);letter-spacing:-1.8px;margin:15px 0}h1 em{color:#769263;font-style:normal}.subtitle{color:var(--muted);max-width:720px;line-height:1.7}.banner{display:flex;align-items:center;gap:18px;background:#e9efdc;border:1px solid #dbe5cb;border-radius:13px;padding:20px 24px;margin:27px 0 35px}.banner>span{font-size:28px;color:#7f935c}.banner p{font-size:13px;color:#6d7c5c;margin:6px 0 0}.banner button{margin-left:auto;white-space:nowrap}.layout{display:grid;grid-template-columns:310px 1fr;gap:38px}.sidebarTitle{display:flex;align-items:center;justify-content:space-between}.sidebarTitle h2{font-size:14px;margin:0}.sidebarTitle span{font-size:12px;color:#768762}.muted{font-size:11px;color:var(--muted);line-height:1.6}nav{display:grid;gap:5px;margin-top:17px}nav button{display:flex;align-items:center;gap:12px;text-align:left;width:100%;border:1px solid transparent;padding:12px;border-radius:10px;background:transparent;color:#4f6457;font-size:13px}nav button:hover{background:#edf1e5}nav button.active{background:#e4ecd8;border-color:#d1debf}nav small{display:block;font-size:10px;color:#7c8974;margin-top:4px}.number{flex:0 0 26px;width:26px;height:26px;display:grid;place-items:center;background:#edf1e6;border-radius:7px;color:#71835f;font-size:12px}.completed .number{background:#2b654e;color:white}.session{display:flex;justify-content:space-between;font-size:11px;letter-spacing:1px;color:#758569;font-weight:700}.progress{height:5px;background:#e1e8d7;border-radius:6px;margin:12px 0 21px;overflow:hidden}#bar{height:100%;background:#8aa86d;transition:width .25s}article{background:white;border:1px solid var(--line);border-radius:17px;padding:28px 30px}.exerciseHead{display:flex;justify-content:space-between;gap:12px;font-size:11px;color:#809075}#badge{background:#eff3e5;border-radius:5px;padding:6px 9px}article h2{font-size:24px;letter-spacing:-.6px;margin:24px 0 10px}#context{color:#73816d;font-size:14px;line-height:1.7}#diagram{margin:25px auto;max-width:520px}svg{width:100%;max-height:250px;overflow:visible}svg text{font:14px system-ui;fill:#385940}.grid{display:grid;gap:5px;max-width:360px;margin:0 auto}.cell{height:38px;border:1px solid #cfdabc;background:#eff3e7;border-radius:4px}.cell.on{background:#92b578;border-color:#7e9f66}button.cell:hover{border:2px solid #315e43}.grid button:focus-visible{outline:3px solid #315e43;outline-offset:2px}#inputs{display:flex;align-items:center;justify-content:center;gap:13px;margin:25px 0}input{width:115px;padding:12px;text-align:center;border:1px solid #c9d4c0;border-radius:8px;background:#fafcf6;font-size:22px;color:#315c45}.fractionInputs{display:flex;flex-direction:column;gap:7px}.fractionInputs input{width:75px}.fractionInputs input:first-child{border-bottom:2px solid #8ba179}.unit{font-size:18px}.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;border-top:1px solid #edf0e6;padding-top:22px}.primary,.secondary{border:0;border-radius:8px;padding:13px 17px;font-size:13px;font-weight:650}.primary{background:var(--green);color:white}.primary:hover{background:#357258}.secondary{background:#eff3e5;color:#62794a}.textButton{border:0;background:transparent;color:#718063;font-size:12px;padding:12px 0;text-align:left;text-decoration:underline;text-underline-offset:3px}#feedback{line-height:1.7;font-size:14px}#feedback:not(:empty){padding:14px;background:#edf5e6;border-radius:8px;margin-top:18px}#feedback.error{background:#fff2e3;color:#815a2d}#next{margin-top:17px}.lesson{display:flex;gap:17px;padding:23px;background:#ecf1e3;border-radius:12px;margin-top:22px}.lesson>span{font-size:26px;color:#75925d}.lesson h3{font-size:13px;margin:0 0 8px}.lesson p{font-size:13px;line-height:1.8;margin:8px 0;color:#6e805c}.lesson details{font-size:12px;margin-top:10px}.lesson summary{cursor:pointer;font-weight:650}.reference{font-size:11px;color:#8a9581;line-height:1.8;margin:18px 0}footer{display:flex;justify-content:space-between;gap:20px;border-top:1px solid var(--line);padding:24px 0;margin-top:30px;font-size:11px;color:#8b967f}button:disabled{opacity:.55;cursor:default}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #91ac76;outline-offset:3px}[hidden]{display:none!important}@media(max-width:820px){.layout{grid-template-columns:1fr;gap:25px}nav{grid-template-columns:repeat(2,1fr)}nav button{font-size:12px}.banner{flex-wrap:wrap}.banner button{margin-left:0}main{padding:25px 17px 0}article{padding:24px 20px}h1{letter-spacing:-1px}footer span{max-width:65%}header{padding:0 20px}.cell{height:32px}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}

.downloadPanel{display:flex;align-items:center;justify-content:space-between;gap:20px;background:#fff;border:2px solid #a0b989;border-radius:13px;padding:20px 24px;margin:26px 0}.downloadLink{display:inline-block;text-decoration:none}.downloadPanel p{font-size:12px;color:var(--muted);margin:10px 0 0}.downloadPanel>a{color:var(--green);font-size:12px}.topicGroup{font-size:11px;letter-spacing:.5px;text-transform:uppercase;color:#7b886c;margin:18px 10px 7px;grid-column:1/-1}.expression{display:flex;align-items:center;justify-content:center;gap:20px;font-size:27px;margin:25px 0}.expression:empty{display:none}.mathFraction{display:inline-flex;flex-direction:column;min-width:34px;text-align:center;line-height:1.45}.mathFraction span{padding:0 7px}.mathFraction span:first-child{border-bottom:2px solid currentColor}.compareChoice{padding:10px 23px;border:1px solid #ccd9bc;background:#f7f9f1;border-radius:9px;font-size:23px;color:var(--green)}.compareChoice.selected{background:#dce9cb;border:2px solid #78935e}@media(max-width:600px){.downloadPanel{align-items:flex-start;flex-direction:column;padding:18px}.downloadLink{font-size:12px}.expression{gap:14px}}