:root{--ink:#0b1739;--muted:#58637c;--line:#dce2e9;--accent:#007f73;--tint:#eaf5f3;--bad:#ae3547;--bad-bg:#fff1f3;font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:#fff;font-synthesis:none}*{box-sizing:border-box}body{margin:0}button,select,input{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.45}a{color:var(--accent)}button:focus-visible,a:focus-visible,select:focus-visible,input:focus-visible{outline:3px solid #2b9bca;outline-offset:4px}button{border:0}svg{width:23px;height:23px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}.header{height:74px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 32px;gap:24px}.brand{display:flex;gap:18px;align-items:center;text-decoration:none;color:var(--ink);white-space:nowrap;font-size:19px}.brand strong{font-size:30px;letter-spacing:-1px}.slash{color:var(--muted)}#modes{height:100%;display:flex;gap:32px}#modes button{background:transparent;color:var(--muted);padding:0 4px;border-bottom:3px solid transparent;font-size:16px;font-weight:550}#modes button.active{color:var(--ink);border-color:var(--accent)}.layout{display:grid;grid-template-columns:288px minmax(0,1fr);min-height:calc(100vh - 74px)}aside{border-right:1px solid var(--line);padding:32px 18px;display:flex;flex-direction:column;gap:80px}#topics{display:flex;flex-direction:column;gap:12px}#topics button{display:flex;align-items:center;gap:22px;text-align:left;padding:17px 18px;background:transparent;color:#33415e;border-radius:7px;font-size:16px;white-space:nowrap}#topics button.active{background:var(--tint);color:var(--accent)}#topics button:hover{background:#f2f7f7}.rail-note{padding:0 20px;font-size:15px;line-height:1.7;color:var(--muted)}.rail-note small{display:block;margin-top:12px;font-size:12px}main{padding:50px 60px 40px;max-width:1360px;width:100%;margin:0 auto}h1{font-size:clamp(32px,3.8vw,56px);line-height:1.12;letter-spacing:-2px;margin:0 0 10px;font-weight:730}p.lead{font-size:23px;line-height:1.5;color:var(--muted);margin:0 0 38px}h2{font-size:28px;line-height:1.4;letter-spacing:-.7px;margin:34px 0 24px}h3{font-size:20px;line-height:1.45}.settings{display:grid;grid-template-columns:1.25fr 1fr .84fr;gap:20px;margin:34px 0 36px;align-items:stretch}.field{position:relative;border:1px solid var(--line);border-radius:6px;padding:11px 15px 7px;min-width:0}.field span{display:block;color:var(--muted);font-size:13px;margin-bottom:5px}.field select{width:100%;border:0;background:white;color:var(--ink);font-size:17px;padding:0 22px 3px 0;cursor:pointer;min-width:0}.primary,.secondary{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:56px;padding:14px 28px;border-radius:6px;font-weight:650;font-size:16px;text-decoration:none}.primary{background:var(--accent);color:white}.primary:hover:not(:disabled){background:#006d63}.secondary{background:white;border:1px solid var(--line);color:var(--ink)}.secondary:hover{background:#f4f7f8}.text-button{background:transparent;padding:10px 4px;color:var(--muted);text-decoration:underline;font-size:15px}.quiz{border-top:1px solid var(--line);padding-top:32px}.meta{display:flex;justify-content:space-between;gap:15px;color:var(--muted);font-size:14px}.bar{height:9px;background:#e7ebef;border-radius:20px;margin:12px 0 36px;overflow:hidden}.bar div{height:100%;background:var(--accent);border-radius:20px;transition:width .2s}.question{font-size:27px;margin:0 0 23px;line-height:1.4;letter-spacing:-.7px}.hint{font-size:14px;color:var(--muted);margin:-8px 0 18px}.answers{border:0;padding:0;margin:0;display:grid;gap:12px;min-width:0}.answer{display:flex;align-items:center;gap:18px;border:1px solid var(--line);border-radius:6px;padding:17px 18px;min-height:62px;font-size:18px;line-height:1.45;cursor:pointer}.answer:hover{border-color:#819992;background:#fafcfb}.answer.selected{border-color:var(--accent);background:#f4fbf9}.answer.correct{border-color:var(--accent);background:var(--tint)}.answer.wrong{border-color:var(--bad);background:var(--bad-bg)}.answer input{width:21px;height:21px;accent-color:var(--accent);margin:0;flex-shrink:0}.answer .mark{margin-left:auto;font-size:12px;font-weight:650;white-space:nowrap}.actions{display:flex;justify-content:space-between;align-items:center;gap:18px;margin:30px 0 23px}.actions .primary{min-width:250px}.source{border-top:1px solid var(--line);padding-top:15px;font-size:13px;line-height:1.7;color:var(--muted)}.feedback{padding:20px 24px;margin-top:22px;border-left:3px solid var(--accent);background:var(--tint);line-height:1.65}.feedback.bad{border-color:var(--bad);background:var(--bad-bg)}.feedback strong{display:block;font-size:18px}.feedback p{margin:7px 0 0}.notice{font-size:14px;line-height:1.7;color:var(--muted);padding:16px 0}.resume{display:flex;align-items:center;justify-content:space-between;gap:20px;background:var(--tint);padding:18px 22px;margin:24px 0;border-radius:6px}.resume p{margin:0;line-height:1.5}.intro{padding:12px 0 24px}.intro p{max-width:720px;line-height:1.8;color:var(--muted);font-size:17px}.summary{display:flex;gap:48px;flex-wrap:wrap;border-block:1px solid var(--line);padding:26px 0;margin:30px 0}.stat strong{font-size:38px;display:block;letter-spacing:-1px}.stat span{font-size:14px;color:var(--muted)}.review{border-top:1px solid var(--line);padding:22px 0}.review summary{cursor:pointer;font-size:17px;font-weight:600;line-height:1.6}.review p{line-height:1.7;color:var(--muted)}.review .status{color:var(--accent);font-size:13px;display:block}.review .status.bad{color:var(--bad)}.topic-stat{display:grid;grid-template-columns:1fr auto;gap:12px;margin:23px 0}.topic-stat .bar{grid-column:1/-1;margin:0;height:6px}.empty{padding:30px 0;color:var(--muted);line-height:1.8}.utilities{display:flex;gap:16px;flex-wrap:wrap;margin:30px 0}.danger{color:var(--bad)}.timer{font-variant-numeric:tabular-nums;font-weight:650;color:var(--ink)}.visually-hidden{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.storage-warning{color:var(--bad);font-size:13px;line-height:1.6}dialog{border:1px solid var(--line);border-radius:10px;max-width:480px;padding:28px;color:var(--ink);box-shadow:0 20px 80px #0b17392b}dialog::backdrop{background:#0b173944}dialog p{line-height:1.7}dialog .utilities{margin-bottom:0}@media(min-width:1600px){main{padding-top:60px}}@media(max-width:1150px){.layout{grid-template-columns:240px 1fr}aside{padding-inline:10px}#topics button{gap:14px;padding-inline:14px;font-size:14px}main{padding:40px 32px}h1{font-size:42px}.settings{gap:12px;grid-template-columns:1.2fr 1fr}.settings>.primary{grid-column:1/-1;min-height:50px}p.lead{font-size:20px}.question{font-size:24px}}@media(max-width:760px){.header{height:auto;min-height:72px;flex-wrap:wrap;padding:16px 20px 0;gap:12px}.brand{font-size:15px;gap:12px}.brand strong{font-size:26px}#modes{height:44px;gap:24px}#modes button{font-size:14px}.layout{display:block;min-height:0}aside{display:block;border-right:0;border-bottom:1px solid var(--line);padding:10px 12px}#topics{flex-direction:row;overflow-x:auto;gap:4px}#topics button{font-size:13px;padding:11px 12px;gap:8px}#topics svg{width:18px;height:18px}.rail-note{display:none}main{padding:30px 20px}h1{font-size:34px;letter-spacing:-1.3px}p.lead{font-size:17px;margin-bottom:25px}.settings{margin:26px 0;gap:12px;grid-template-columns:1fr 1fr}.field{padding:10px;}.field select{font-size:14px}.field span{font-size:12px}.quiz{padding-top:24px}.bar{margin-bottom:26px}.question{font-size:23px}.answer{font-size:16px;gap:12px;padding:15px 13px}.answer .mark{white-space:normal;text-align:right;max-width:65px}.actions{gap:12px;align-items:stretch}.actions .primary{min-width:0;flex:1;padding-inline:16px}.text-button{font-size:13px}.meta{font-size:12px}.feedback{padding:15px 17px;font-size:15px}.resume{align-items:stretch;flex-direction:column}.summary{gap:28px}.stat strong{font-size:32px}.primary,.secondary{font-size:14px;padding:13px 20px}.source{font-size:12px}.utilities{gap:10px}.intro{padding-top:0}}@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}
/* Keep round controls compact so the question remains the visual focus. */
.settings{margin-bottom:22px}
.settings~.notice{margin:14px 0 24px;padding:0;font-size:13px}
@media(max-width:760px){.settings~.notice{margin:14px 0 22px;line-height:1.65}.meta>span:last-child{text-align:right}}