:root{color-scheme:dark;--bg:#061426;--panel:#0d2038;--panel2:#08182b;--line:#24486e;--text:#e8f1ff;--muted:#9fb4cf;--cyan:#43d9ff;--blue:#1677ff;--green:#27c93f;--red:#ff7b72}*{box-sizing:border-box}html{min-height:100%;background:var(--bg)}body{min-height:100vh;margin:0;background:radial-gradient(circle at 50% 0,#0c2745 0,#061426 42%,#040c17);color:var(--text);font:16px/1.6 Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}main{width:min(980px,calc(100% - 32px));margin:0 auto;padding:24px 0 70px}nav{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:42px;font:700 14px ui-monospace,SFMono-Regular,monospace}a{color:var(--cyan);text-underline-offset:3px}h1{font-size:clamp(2.5rem,6vw,4.5rem);line-height:1.02;letter-spacing:-.04em;margin:0 0 12px}h2{margin:0;color:#d9eaff}h3{font-size:clamp(1.35rem,3vw,2rem);line-height:1.25;margin:28px 0 8px}.meta{color:var(--muted)}.card{background:linear-gradient(145deg,#0d2038fa,#071423fa);border:1px solid var(--line);border-radius:18px;padding:24px;margin-top:22px;box-shadow:0 24px 70px #00000047}.bar{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.score{font-weight:800;color:var(--cyan);margin-right:auto}.btn{border:1px solid #2d75b6;border-radius:10px;background:linear-gradient(180deg,#2184ff,#1266d4);color:#fff;padding:11px 16px;font-weight:800;cursor:pointer}.btn:hover,.btn:focus-visible{filter:brightness(1.1);outline:2px solid rgba(67,217,255,.45);outline-offset:2px}.options{display:grid;gap:10px;margin-top:18px}.option{display:block;width:100%;margin:0;padding:14px 16px;text-align:left;background:var(--panel2);border:1px solid #315b87;border-radius:11px;color:var(--text);cursor:pointer;transition:border-color .15s,transform .15s,background .15s}.option:hover:not(:disabled),.option:focus-visible{border-color:var(--cyan);background:#0b2138;outline:none;transform:translateY(-1px)}.option:disabled{cursor:default;opacity:.98}.correct{border-color:var(--green);background:#102d24}.wrong{border-color:var(--red);background:#321c24}.option.correct{color:#c9ffd2}.option.wrong{color:#ffd0cc}@media(max-width:650px){main{width:min(100% - 20px,650px);padding-top:16px}.card{padding:18px}nav{margin-bottom:28px}.bar{align-items:flex-start}.score{width:100%;margin-right:0}.btn{width:100%}}