:root{--blue:#1565c0;--dark:#0d47a1;--pale:#e3f2fd;--ink:#172033;--muted:#64748b;--line:#dce5ef;--green:#15803d;--red:#c62828}*{box-sizing:border-box}body{margin:0;background:#f5f8fc;color:var(--ink);font:16px/1.45 Arial,sans-serif}button,a{font:inherit}button{cursor:pointer}.brand{display:flex;align-items:center;gap:10px;color:var(--dark);font-weight:800;text-decoration:none}.logo{width:44px;height:44px;border-radius:50%}.nav,.topbar{height:68px;display:flex;align-items:center;justify-content:space-between;padding:0 max(18px,calc((100vw - 1080px)/2));background:#fff;border-bottom:1px solid var(--line)}.hero{min-height:570px;display:grid;grid-template-columns:1.2fr .8fr;gap:50px;align-items:center;width:min(1080px,calc(100% - 36px));margin:auto;padding:56px 0}.eyebrow,.kicker{color:var(--blue);font-size:12px;font-weight:800;letter-spacing:.12em}.hero h1{font-size:clamp(44px,7vw,78px);line-height:1.02;margin:12px 0 22px}.hero h1 span{color:var(--blue)}.hero p{max-width:610px;color:var(--muted);font-size:19px}.actions{display:flex;gap:12px;flex-wrap:wrap;margin:28px 0}.primary,.secondary{min-height:52px;border:0;border-radius:14px;padding:0 22px;font-weight:800}.primary{background:var(--blue);color:#fff}.secondary{background:#fff;color:var(--dark);border:1px solid var(--line)}.disabled{opacity:.45;pointer-events:none}.preview{display:grid;gap:16px}.preview-card,.card{background:#fff;border:1px solid var(--line);border-radius:22px;box-shadow:0 16px 40px #1d4b7a12}.preview-card{padding:25px}.preview-card strong{display:block;color:var(--blue);font-size:48px}.features{display:grid;grid-template-columns:repeat(4,1fr);background:var(--dark);color:#fff}.features div{text-align:center;padding:24px}.features b,.features span{display:block}.features b{font-size:26px}.features span{opacity:.75;font-size:13px}.shell{width:min(1040px,calc(100% - 28px));margin:34px auto 100px}.welcome h1{font-size:42px;margin:8px 0}.welcome p{color:var(--muted)}.grid{display:grid;grid-template-columns:1.4fr 1fr;gap:18px;margin-top:28px}.card{padding:25px}.start{background:linear-gradient(135deg,#0d47a1,#1976d2);color:#fff}.start .kicker{color:#bbdefb}.start a{display:inline-flex;margin-top:20px;background:#fff;color:var(--dark);text-decoration:none;padding:14px 18px;border-radius:12px;font-weight:800}.profile{display:flex;align-items:center;gap:14px}.avatar{display:grid;place-items:center;width:54px;height:54px;border-radius:50%;background:var(--pale);color:var(--dark);font-size:22px;font-weight:800}.profile strong,.profile span,.profile em{display:block}.profile span{color:var(--muted)}.profile em{color:var(--blue);font-size:12px}.stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.stats div{background:#f4f7fb;border-radius:14px;padding:16px;text-align:center}.stats strong,.stats span{display:block}.stats strong{font-size:28px;color:var(--dark)}.stats span{font-size:12px;color:var(--muted)}.review strong{font-size:54px;color:var(--blue)}.review a{color:var(--blue);font-weight:800;text-decoration:none}.history-row{display:grid;grid-template-columns:1fr auto auto;gap:16px;padding:11px 0;border-bottom:1px solid var(--line)}.passed{color:var(--green)}.failed{color:var(--red)}.quiz{width:min(720px,calc(100% - 24px));margin:24px auto 110px}.meta{display:flex;justify-content:space-between;color:var(--muted);margin-bottom:12px}.progress{height:4px;background:#dbe8f7}.progress span{display:block;height:100%;background:var(--blue)}.question{padding:clamp(20px,5vw,38px)}.question h1{font-size:clamp(22px,4vw,29px)}.chips{display:flex;gap:8px}.chip{background:var(--pale);color:var(--dark);padding:6px 11px;border-radius:9px;font-size:12px;font-weight:800}.options{display:grid;gap:12px;margin-top:22px}.option{display:grid;grid-template-columns:36px 1fr auto;align-items:center;gap:12px;min-height:64px;text-align:left;background:#fff;border:1.5px solid #cdd8e5;border-radius:15px;padding:12px}.letter{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:#edf2f7;font-weight:800}.option.correct{border-color:#43a66d;background:#e8f5e9;color:#175b36}.option.wrong{border-color:#e57373;background:#ffebee;color:#8f1e1e}.feedback{margin-top:18px;padding:14px;border-radius:12px}.feedback.good{background:#e8f5e9;color:#175b36}.feedback.bad{background:#ffebee;color:#8f1e1e}.bottom{position:fixed;bottom:0;left:0;right:0;background:#fffffff2;border-top:1px solid var(--line);padding:12px}.bottom button{display:block;width:min(720px,100%);margin:auto}.results{text-align:center}.results .logo{width:78px;height:78px}.results h1{font-size:64px;color:var(--dark);margin:8px}.overlay{position:fixed;inset:0;background:#0f243c75;display:flex;align-items:flex-end;justify-content:center}.sheet{background:#fff;width:min(620px,100%);max-height:88vh;overflow:auto;border-radius:24px 24px 0 0;padding:22px}.sheet-head{display:flex;justify-content:space-between}.topics{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:18px 0}.topic{padding:13px;border:1px solid var(--line);border-radius:12px}.topic:has(input:checked){background:#f3f9ff;border-color:var(--blue)}.close{border:0;background:#eef2f6;border-radius:50%;width:36px;height:36px;font-size:22px}.empty{text-align:center;padding:55px}.notice{background:#fff7db;color:#7a5500;border:1px solid #f1d681;border-radius:12px;padding:11px 14px;margin-top:16px}@media(max-width:760px){.hero{grid-template-columns:1fr;padding:40px 0}.preview{display:none}.features{grid-template-columns:repeat(2,1fr)}.grid{grid-template-columns:1fr}.topics{grid-template-columns:1fr}.nav,.topbar{padding:0 16px}.hero h1{font-size:46px}}