:root{--ink:#17233a;--muted:#637286;--accent:#df6848;--teal:#187263;--line:#e1e5e9;--paper:#faf8f3}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.65 system-ui,-apple-system,sans-serif}header{max-width:1240px;margin:auto;padding:24px;display:flex;gap:24px;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:12px;font-weight:800;text-decoration:none}.brand small{display:block;letter-spacing:.16em;font-size:10px;color:var(--accent)}nav{display:flex;align-items:center;gap:12px;flex-wrap:wrap}a{color:inherit}header nav{font-size:13px}header nav a{text-decoration:none}main{max-width:1200px;margin:auto;padding:30px 24px 60px}h1{font:700 clamp(32px,4vw,48px)/1.12 Georgia,serif;letter-spacing:-.025em;margin:10px 0 16px}h2{font-size:21px;line-height:1.35;margin:8px 0 18px}p{margin:12px 0}.eyebrow{font-size:11px;letter-spacing:.14em;font-weight:800;color:var(--accent)}.intro{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:15px 0 25px}.intro p:not(.eyebrow){color:var(--muted)}.tag{padding:10px 16px;border:1px solid var(--line);border-radius:30px;white-space:nowrap;background:white;font-size:13px}.panel{background:white;border:1px solid var(--line);border-radius:18px;padding:28px}.dashboard-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:24px}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.stat{border:1px solid var(--line);padding:20px;border-radius:14px;background:white}.stat b{display:block;font-size:30px;line-height:1.2}.stat span{font-size:12px;color:var(--muted)}.fine{color:var(--muted);font-size:12px}.resume{display:flex;justify-content:space-between;gap:20px;align-items:center;border-left:4px solid var(--teal);margin-top:22px}.resume p{font-size:13px;color:var(--muted)}button,.primary{border:1px solid #c9d1dc;border-radius:10px;background:white;color:var(--ink);font:700 14px/1.3 system-ui;padding:12px 16px;cursor:pointer;min-height:44px;text-decoration:none;display:inline-flex;justify-content:center;align-items:center}.primary{background:var(--ink);color:white;border-color:var(--ink)}button:disabled{opacity:.5;cursor:not-allowed}button:hover:enabled{border-color:var(--teal)}:focus-visible{outline:3px solid #1689a4;outline-offset:3px}form{display:grid;gap:15px}.fields{display:grid;grid-template-columns:1fr 1fr;gap:14px}label{display:grid;gap:7px;font-size:13px;font-weight:650}select{width:100%;min-width:0;max-width:100%;font:14px system-ui;border:1px solid #c9d1dc;border-radius:9px;padding:12px;background:#fcfcfd;color:var(--ink)}#pool-count{font-size:13px;color:var(--teal);margin:0}.topic-row{padding:15px 0;border-bottom:1px solid var(--line)}.topic-row:last-child{border:0}.topic-row b{display:block;font-size:13px;line-height:1.5}.topic-row span{font-size:12px;color:var(--muted)}progress{display:block;width:100%;height:7px;margin-top:8px;accent-color:var(--teal)}#topics-progress{max-height:480px;overflow:auto;padding-right:8px}.study-top,.study-bottom{display:flex;align-items:center;justify-content:space-between;gap:16px}.study-top h1{font-size:32px}.study-bottom{margin-top:22px;justify-content:flex-start;flex-wrap:wrap}.study-grid{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(270px,1fr);gap:24px;align-items:start;margin-top:20px}.question-meta{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px;font-size:12px;color:var(--muted)}.question-meta button{font-size:12px}.figure-button{display:block;width:100%;height:auto;border:1px solid var(--line);background:#fafbf9;padding:12px;margin:18px 0}.figure-button img{display:block;max-width:100%;width:auto;max-height:460px;margin:auto;object-fit:contain}.figure-button span{display:block;margin-top:8px;font-size:11px;color:var(--muted)}.rich{overflow-wrap:break-word}.rich table{width:100%;border-collapse:collapse;font-size:14px}.rich td,.rich th{padding:7px;border:1px solid var(--line)}.stem{font-weight:650;margin:22px 0}.rich img{max-width:100%}fieldset{padding:0;border:0;margin:0}legend{font-size:12px;color:var(--muted);margin-bottom:10px}.choice{display:flex;align-items:flex-start;gap:12px;border:1px solid var(--line);border-radius:10px;padding:12px;margin-bottom:9px;cursor:pointer;font-weight:400;font-size:15px}.choice input{margin:5px 0 0;accent-color:var(--teal);flex-shrink:0}.choice b{font-size:13px}.choice.selected{border-color:var(--teal);background:#f0f8f5}.choice.correct{border:2px solid var(--teal)}.choice.incorrect{border-color:#bb4d42;background:#fff5f0}#feedback{padding:0;margin:16px 0;font-weight:650}.error{color:#a7342f}.success{color:var(--teal)}#global-message:empty{display:none}#global-message{font-size:14px;margin-bottom:18px}#question-nav button{min-width:42px;padding:9px}.current{box-shadow:inset 0 -3px var(--accent)}.answered{background:#e9f4ef}.solution{border-top:4px solid var(--teal)}.solution p{font-size:14px;color:var(--muted)}.solution ol{padding-left:22px}.solution li{margin-bottom:20px}.solution h3{font-size:16px}.calculation{background:#f4f6f8;padding:12px;border-radius:8px;font-size:15px;overflow-x:auto}.math-frac{display:inline-flex;flex-direction:column;vertical-align:middle;align-items:stretch;text-align:center;line-height:1.15;margin:0 .16em;white-space:nowrap;break-inside:avoid}.math-num,.math-den{display:block;padding:.12em .22em}.math-num{border-bottom:1.2px solid currentColor}.math-frac .math-frac{font-size:.9em}.actions{display:flex;gap:12px;flex-wrap:wrap}dialog{width:min(1100px,calc(100% - 24px));max-height:92vh;border:1px solid var(--line);border-radius:14px;padding:18px;color:var(--ink)}dialog::backdrop{background:#17233ab0}dialog img{display:block;max-width:100%;max-height:78vh;margin:10px auto;object-fit:contain}dialog button{margin-left:auto;display:flex}footer{text-align:center;color:var(--muted);font-size:12px;padding:25px}[hidden]{display:none!important}@media(max-width:850px){header{align-items:flex-start;flex-direction:column}.dashboard-grid,.study-grid{grid-template-columns:1fr}.intro{align-items:flex-start;flex-direction:column}.resume{align-items:flex-start;flex-direction:column}.stats{grid-template-columns:1fr 1fr}.study-top{align-items:flex-start}.question-meta{align-items:flex-start;flex-wrap:wrap}}@media(max-width:480px){main{padding:20px 14px 40px}header{padding:20px 14px}.panel{padding:20px}.stat{padding:15px}.fields{grid-template-columns:1fr}.study-top{flex-direction:column}.study-bottom button{flex:1}.rich table{font-size:12px}.choice{font-size:14px}.question-meta button{width:100%}.brand{font-size:14px}}
input:not([type=radio]){width:100%;border:1px solid #c9d1dc;border-radius:9px;padding:12px;font:16px system-ui;color:var(--ink)}.student-price{min-width:250px;border-top:4px solid var(--accent)}.student-price>span{font-size:11px;letter-spacing:.08em;font-weight:750}.student-price>b{display:block;font-size:64px;line-height:1.2;margin-top:12px}.student-price b small{font-size:24px}.student-price p{font-size:13px}#student-signout{display:inline-block;margin:12px;font-size:13px}#student-email{overflow-wrap:anywhere}#replace-dialog{max-width:520px}#replace-dialog button{margin:0}