:root{--primary-color:#6366f1;--secondary-color:#818cf8;--bg-color:#0f172a;--card-bg:#1e293b;--text-color:#f1f5f9;--text-muted:#94a3b8;--error-color:#ef4444;--success-color:#10b981;--border-color:#334155;--input-bg:#0f172a;--button-hover:#4f46e5}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-color);justify-content:center;min-height:100vh;font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;line-height:1.5;display:flex}#root{width:100%;max-width:600px;padding:2rem 1rem}.container{background:var(--card-bg);text-align:center;border:1px solid var(--border-color);border-radius:1rem;padding:2rem;box-shadow:0 10px 15px -3px #0000004d}h1{color:var(--primary-color);letter-spacing:-.025em;margin-bottom:1.5rem;font-weight:800}.category-list{grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:1rem;margin-top:1.5rem;display:grid}button{background-color:var(--primary-color);color:#fff;cursor:pointer;border:none;border-radius:.5rem;padding:.75rem 1rem;font-size:1rem;font-weight:600;transition:all .2s}button:hover{background-color:var(--button-hover);transform:translateY(-1px)}button:active{transform:translateY(0)}button:disabled{cursor:not-allowed;background-color:#475569;transform:none}.secondary-btn{background-color:#334155}.secondary-btn:hover{background-color:#475569}.quiz-question{color:var(--text-color);margin-bottom:2rem;font-size:1.35rem;font-weight:600}.options-list{flex-direction:column;gap:.85rem;display:flex}.option-btn{color:var(--text-color);text-align:left;border:1px solid var(--border-color);background-color:#334155}.option-btn:hover{border-color:var(--secondary-color);background-color:#475569}.leaderboard-table{border-collapse:collapse;width:100%;margin-top:1.5rem}.leaderboard-table th{text-align:left;color:var(--text-muted);text-transform:uppercase;letter-spacing:.05em;font-size:.875rem}.leaderboard-table th,.leaderboard-table td{border-bottom:1px solid var(--border-color);padding:1rem .75rem}input{background-color:var(--input-bg);color:var(--text-color);border:1px solid var(--border-color);border-radius:.5rem;outline:none;padding:.85rem;font-size:1rem;transition:border-color .2s}input:focus{border-color:var(--primary-color)}.loading-spinner{border:4px solid #ffffff1a;border-left-color:var(--primary-color);border-radius:50%;width:40px;height:40px;margin:2rem auto;animation:1s linear infinite spin}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.timer-clock{color:var(--primary-color);border:2px solid var(--primary-color);border-radius:.5rem;min-width:60px;padding:.25rem .75rem;font-family:Courier New,Courier,monospace;font-size:1.25rem;font-weight:700}.timer-low{color:var(--error-color);border-color:var(--error-color);animation:.5s infinite pulse}@keyframes pulse{0%{transform:scale(1)}50%{transform:scale(1.05)}to{transform:scale(1)}}#reader{border:none!important}#reader__scan_region{background:#000;border-radius:.5rem}#reader__dashboard_section_csr button{background-color:var(--secondary-color)!important;margin-top:1rem!important}#reader__status_span{color:var(--text-muted)!important}@media (width<=480px){.container{padding:1.5rem}}