:root{--bg:#f6f7f9;--card:#fff;--border:#e3e5e9;--text:#16181d;--muted:#6b7280;--accent:#2f6df0;--correct:#2f9e5f;--correct-bg:#e8f6ed;--wrong:#d1453b;--wrong-bg:#fdecea;--radius:12px}@media (prefers-color-scheme:dark){:root{--bg:#101216;--card:#191c22;--border:#2a2f38;--text:#eceef2;--muted:#9aa1ad;--accent:#6f9bff;--correct-bg:#14301f;--wrong-bg:#331a18}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;-webkit-text-size-adjust:100%}.container{max-width:900px;margin:0 auto;padding:20px 16px 64px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:20px}.topbar h1{font-size:20px;margin:0}.muted{color:var(--muted);font-size:14px;margin:4px 0 0}.card{background:var(--card);border:1px solid 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