:root{font-family:Inter,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;color:#203229;background:#f6f5ef}*{box-sizing:border-box}body{margin:0}.shell{max-width:1040px;margin:auto;padding:30px 5vw 80px}header{display:flex;justify-content:space-between;align-items:center}.brand{font-weight:800;font-size:22px;letter-spacing:-1px;text-decoration:none;color:#203229}.brand span{font-size:25px;color:#427759}.pill{font-size:11px;color:#708478;border:1px solid #d5ded5;padding:8px 12px;border-radius:30px}.hero{padding:80px 0 70px;max-width:720px}.eyebrow,.caption{font-size:11px;letter-spacing:.13em;color:#758a79;font-weight:750}h1{font-size:clamp(48px,8vw,86px);line-height:.99;letter-spacing:-.065em;margin:23px 0}h1 em{font-style:normal;color:#648e70}.hero p{max-width:475px;font-size:17px;line-height:1.65;color:#748177}.start{border:0;background:#244f3b;color:#fff;border-radius:12px;padding:16px 19px;font:inherit;font-weight:700;cursor:pointer;min-width:220px;text-align:left}.start span{float:right}.hero-note{font-size:12px;color:#94a095;margin-top:14px}.progress{background:#e6eee4;border-radius:22px;padding:28px 32px;display:flex;align-items:center;justify-content:space-between;gap:28px}h2{letter-spacing:-.04em;font-size:25px;line-height:1.15;margin:12px 0}.stats{display:flex;gap:40px}.stats b{display:block;font-size:29px;letter-spacing:-.05em}.stats span{font-size:12px;color:#788a7b}.path{padding-top:55px}.section-head{display:flex;align-items:end;justify-content:space-between;margin-bottom:18px}.small{font-size:13px;color:#839187}.topics{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.topic{font:inherit;text-align:left;background:#fff;border:1px solid #e9ece5;border-radius:17px;padding:20px;cursor:pointer;min-height:140px;color:#23382c}.topic:hover{border-color:#85aa8e}.topic .symbol{display:block;color:#648f70;font-size:24px}.topic strong{display:block;margin:19px 0 6px}.topic small{color:#91a097}.foot{font-size:12px;color:#96a198;line-height:1.5;margin-top:24px}.practice-head{display:flex;justify-content:space-between;align-items:center;margin:55px 0 20px}.back{background:none;border:0;font:inherit;color:#567760;cursor:pointer;padding:8px 0}.question-card{max-width:680px;background:#fff;border:1px solid #e5ebe3;border-radius:22px;padding:clamp(22px,5vw,42px)}.question-card h2{font-size:clamp(24px,4vw,34px);line-height:1.3;margin:23px 0}form{display:grid;gap:10px;margin-top:30px}label{font-weight:700;font-size:13px}input{font:inherit;font-size:18px;border:1px solid #cddbcf;border-radius:11px;padding:15px;outline:none}input:focus{border-color:#528a64}.feedback{margin:20px 0;background:#eaf4e9;border-radius:12px;padding:17px;line-height:1.55}.feedback.wrong{background:#fff1e8}.feedback strong{display:block;margin-bottom:5px}#error{background:#fff1e8;border-radius:12px;padding:16px;margin-top:20px;color:#8b4938}button:disabled{opacity:.6;cursor:wait}[hidden]{display:none!important}@media(max-width:650px){.shell{padding:22px 20px 60px}.hero{padding:65px 0 55px}.progress{display:block;padding:25px}.stats{gap:20px;justify-content:space-between;margin-top:25px}.stats b{font-size:24px}.topics{grid-template-columns:repeat(2,1fr)}.topic{padding:16px;min-height:130px}.topic strong{font-size:14px}.path{padding-top:42px}}

.dataset-head{margin-top:52px}.datasets{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:20px}.datasets a{color:#203229;text-decoration:none;background:#fff;border:1px solid #e9ece5;border-radius:15px;padding:17px;display:block}.datasets a:hover{border-color:#85aa8e}.datasets strong,.datasets span{display:block}.datasets strong{font-size:14px}.datasets span{font-size:12px;color:#819086;line-height:1.5;margin-top:9px}@media(max-width:650px){.datasets{grid-template-columns:repeat(2,1fr)}}

.question-card .katex{font-size:1.02em}.question-card h2{overflow-wrap:anywhere}.katex-display{overflow-x:auto;overflow-y:hidden;padding:.15em 0}.feedback .katex{font-size:1.05em}

.choices{display:grid;gap:9px}.choice{display:flex;align-items:flex-start;gap:12px;border:1px solid #dce6dc;border-radius:12px;padding:14px;cursor:pointer;font-size:15px;font-weight:500;line-height:1.5}.choice:has(input:checked){border-color:#4e8962;background:#f0f7f0}.choice input{width:18px;height:18px;flex:none;margin:2px 0;accent-color:#245d40}.choice span{min-width:0}textarea{width:100%;resize:vertical;min-height:150px;font:inherit;line-height:1.55;border:1px solid #cddbcf;border-radius:11px;padding:15px}textarea:focus{outline:none;border-color:#528a64}.rubric-title{margin-top:17px}.feedback ul{padding-left:20px;margin:8px 0 0}.feedback li{margin:7px 0}

.filter-label{display:block;font-size:12px;font-weight:700;color:#63776a;margin:0 0 8px}select{font:inherit;border:1px solid #d4dfd3;border-radius:10px;color:#244f3b;background:white;padding:10px 14px;margin-bottom:17px;max-width:100%}
