:root{--bg:#f1f5f6;--panel:#fff;--ink:#102a3a;--muted:#637783;--line:#d6e0e4;--brand:#08747c;--accent:#e99a4b;--bad:#bd3e35;--good:#197a52}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at top right,#dff1ef 0,transparent 27rem),var(--bg);color:var(--ink);font:16px/1.5 Inter,ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif}header{background:linear-gradient(125deg,#102f42,#075d65);color:#fff;padding:46px max(24px,calc((100% - 1040px)/2));display:flex;justify-content:space-between;gap:18px;align-items:start}.eyebrow{letter-spacing:.14em;font-size:.72rem;font-weight:750;color:#a8e0dc;margin:0}h1{font-size:clamp(2rem,5vw,3.25rem);letter-spacing:-.035em;line-height:1.05;margin:6px 0}.sub{margin:0;color:#d1e5e7}.icon{border:1px solid #8bb6ba;background:#ffffff12;color:white;border-radius:50%;width:40px;height:40px;font-size:20px}main{max-width:1040px;margin:0 auto;padding:34px 20px 90px}.panel,.question{background:var(--panel);border:1px solid var(--line);border-radius:16px;box-shadow:0 8px 30px #0731410c}.panel{padding:clamp(25px,5vw,50px)}.panel h2{margin-top:0;font-size:clamp(1.6rem,3vw,2.15rem);letter-spacing:-.02em}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}button{font:inherit;cursor:pointer;transition:transform .15s,box-shadow .15s}button:hover{transform:translateY(-1px)}button.primary,button.secondary{border-radius:9px;padding:11px 17px;font-weight:700}.primary{background:var(--brand);color:#fff;border:1px solid var(--brand);box-shadow:0 4px 10px #0066702b}.secondary{background:transparent;color:var(--brand);border:1px solid var(--brand)}.progress-line{height:10px;background:#dbe6e8;border-radius:20px;overflow:hidden}.progress-line div{height:100%;width:0;background:linear-gradient(90deg,var(--brand),#44aaa1);transition:width .2s}.progress-text{display:flex;justify-content:space-between;align-items:center;margin:15px 0 22px;gap:10px;color:var(--muted)}#questions{display:grid;gap:16px}.question{padding:24px;position:relative;overflow:hidden}.question h2{font-size:1.08rem;margin:0 0 13px;line-height:1.45}.options{display:grid;gap:8px}.option{display:flex;gap:10px;padding:11px 13px;border:1px solid var(--line);border-radius:9px;cursor:pointer}.option:has(input:checked){background:#e8f4f3;border-color:var(--brand)}input[type=text]{width:100%;padding:11px 12px;border:1px solid #aebdc7;border-radius:8px;font:inherit;background:var(--panel);color:var(--ink)}input[type=text]:focus{outline:3px solid #72cbc550;border-color:var(--brand)}.answer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(175px,1fr));gap:11px;margin-top:13px}.answer-box{padding:12px;border:1px solid var(--line);border-radius:10px;background:linear-gradient(180deg,#fafdfd,#f4f9f9)}.answer-box label{display:block;font-size:.82rem;font-weight:750;letter-spacing:.03em;color:var(--muted);margin-bottom:6px}.diagram{display:block;max-width:100%;height:auto;border:1px solid var(--line);border-radius:10px;margin:17px auto;background:white;box-shadow:0 5px 14px #07314112}.hint{font-size:.85rem;color:var(--muted);margin:.5rem 0}.sticky{position:sticky;bottom:12px;text-align:center;margin-top:24px}.sticky .primary{box-shadow:0 5px 18px #002c3c3b}.correct{border-color:var(--good)!important;background:#e8f5ed!important}.incorrect{border-color:var(--bad)!important;background:#fff0ef!important}.feedback{margin:14px 0 0;padding:10px 12px;border-left:4px solid var(--brand);background:#eff7f8}.score{font-size:3rem;font-weight:800;color:var(--brand);margin:.1em 0}.review{margin-top:20px}.review li{margin:7px 0}footer{text-align:center;color:var(--muted);padding:20px;font-size:.85rem}@media(prefers-color-scheme:dark){body.dark{--bg:#10212b;--panel:#18313d;--ink:#eff7fa;--muted:#b9cbd4;--line:#34505d}body.dark .option:has(input:checked){background:#17434a}body.dark .feedback{background:#173841}body.dark .incorrect{background:#522b2b!important}body.dark .answer-box{background:#142b36}}@media(max-width:520px){.progress-text{align-items:start;flex-direction:column}.question{padding:17px}.answer-grid{grid-template-columns:1fr}}