:root{--bg-color:#f8fafc;--text-color:#0f172a;--primary:#3b82f6;--primary-hover:#2563eb;--surface:#fff;--border:#e2e8f0;--danger:#ef4444;--success:#22c55e;--radius:12px;--shadow:0 4px 6px -1px #0000001a, 0 2px 4px -2px #0000001a;--glass-bg:#ffffffb3;--glass-border:#ffffff4d}@media (prefers-color-scheme:dark){:root{--bg-color:#0f172a;--text-color:#f8fafc;--primary:#60a5fa;--primary-hover:#3b82f6;--surface:#1e293b;--border:#334155;--glass-bg:#1e293bb3;--glass-border:#ffffff1a}}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-color);min-height:100vh;font-family:Inter,system-ui,-apple-system,sans-serif;line-height:1.5;transition:background-color .3s,color .3s}#root{max-width:1200px;margin:0 auto;padding:2rem}.glass-panel{background:var(--glass-bg);-webkit-backdrop-filter:blur(12px);border:1px solid var(--glass-border);border-radius:var(--radius);box-shadow:var(--shadow);padding:2rem;transition:transform .2s,box-shadow .2s}.glass-panel:hover{transform:translateY(-2px);box-shadow:0 10px 15px -3px #0000001a,0 4px 6px -4px #0000001a}h1,h2,h3{letter-spacing:-.025em;margin-bottom:1rem;font-weight:700}button{background-color:var(--primary);color:#fff;cursor:pointer;border:none;border-radius:8px;padding:.75rem 1.5rem;font-weight:600;transition:background-color .2s,transform .1s}button:hover{background-color:var(--primary-hover)}button:active{transform:scale(.98)}input,select{border:1px solid var(--border);background-color:var(--surface);width:100%;color:var(--text-color);border-radius:8px;outline:none;margin-bottom:1rem;padding:.75rem 1rem;transition:border-color .2s}input:focus,select:focus{border-color:var(--primary);box-shadow:0 0 0 3px #3b82f633}nav{border-bottom:1px solid var(--border);gap:1rem;margin-bottom:2rem;padding-bottom:1rem;display:flex}nav a{color:var(--text-color);border-radius:6px;padding:.5rem 1rem;font-weight:500;text-decoration:none;transition:background-color .2s}nav a:hover{background-color:var(--surface)}table{border-collapse:collapse;width:100%;margin-top:1rem}th,td{text-align:left;border-bottom:1px solid var(--border);padding:1rem}th{background-color:var(--surface);font-weight:600}.grid{gap:1rem;display:grid}.flex{gap:1rem;display:flex}.mt-4{margin-top:1rem}.mb-4{margin-bottom:1rem}.text-center{text-align:center}.option-btn{text-align:left;background-color:var(--surface);width:100%;color:var(--text-color);border:1px solid var(--border);margin-bottom:.5rem;display:block}.option-btn:hover{background-color:var(--border);color:var(--text-color)}.option-btn.correct{background-color:var(--success);color:#fff;border-color:var(--success)}.option-btn.wrong{background-color:var(--danger);color:#fff;border-color:var(--danger)}