*{box-sizing:border-box;margin:0;padding:0;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif}:root{--primary-color:#6366f1;--primary-hover:#4f46e5;--bg-gradient-start:#0f172a;--bg-gradient-end:#1e1b4b;--card-bg:#1e293bb3;--card-border:#ffffff1a;--text-main:#f8fafc;--text-muted:#94a3b8;--success-color:#10b981;--error-color:#ef4444;--warning-color:#f59e0b}body{background:linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));color:var(--text-main);flex-direction:column;align-items:center;min-height:100vh;display:flex;overflow-x:hidden}#app{flex-direction:column;width:100%;max-width:600px;min-height:100vh;padding:2rem 1.5rem;display:flex}.glass-card{background:var(--card-bg);-webkit-backdrop-filter:blur(12px);border:1px solid var(--card-border);border-radius:1.25rem;padding:2rem;transition:transform .3s,box-shadow .3s;box-shadow:0 10px 30px #0003}h1{background:linear-gradient(90deg,#a5b4fc,#c4b5fd);-webkit-text-fill-color:transparent;text-align:center;-webkit-background-clip:text;margin-bottom:.5rem;font-size:2rem;font-weight:800}p.subtitle{color:var(--text-muted);text-align:center;margin-bottom:2rem;font-size:.95rem}.btn{cursor:pointer;border:none;border-radius:.75rem;justify-content:center;align-items:center;width:100%;padding:.875rem 1.5rem;font-size:1rem;font-weight:600;transition:all .2s;display:inline-flex}.btn-primary{background:var(--primary-color);color:#fff;box-shadow:0 4px 14px #6366f166}.btn-primary:hover:not(:disabled){background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 6px 20px #6366f199}.btn:disabled{opacity:.5;cursor:not-allowed}.select-wrapper{width:100%;margin-bottom:1.5rem;position:relative}select{border:1px solid var(--card-border);color:#fff;appearance:none;cursor:pointer;background:#0f172a99;border-radius:.75rem;outline:none;width:100%;padding:1rem 1.5rem;font-size:1rem;transition:border-color .2s}select:focus{border-color:var(--primary-color)}.select-icon{pointer-events:none;color:var(--text-muted);position:absolute;top:50%;right:1.5rem;transform:translateY(-50%)}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:.4s forwards fadeIn}.app-header{border-bottom:1px solid var(--card-border);justify-content:space-between;align-items:center;margin-bottom:2rem;padding-bottom:1rem;display:flex}.stat-pill{background:#ffffff1a;border-radius:2rem;align-items:center;gap:.5rem;padding:.4rem .8rem;font-size:.85rem;font-weight:600;display:flex}.question-container{flex-direction:column;gap:1.5rem;display:flex}.question-text{color:var(--text-main);border-left:4px solid var(--primary-color);background:#0f172a66;border-radius:1rem;padding:1.5rem;font-size:1.25rem;font-weight:500;line-height:1.6}.options-list{flex-direction:column;gap:.75rem;display:flex}.option-btn{border:1px solid var(--card-border);text-align:left;color:var(--text-main);cursor:pointer;background:#1e293b80;border-radius:.75rem;align-items:center;padding:1.25rem 1.5rem;font-size:1.05rem;transition:all .2s;display:flex}.option-btn:hover:not(:disabled){background:#334155cc;border-color:#94a3b84d;transform:translate(4px)}.option-btn.selected{border-color:var(--primary-color);background:#6366f133}.option-btn.correct{border-color:var(--success-color);color:#34d399;background:#10b98126}.option-btn.incorrect{border-color:var(--error-color);color:#f87171;background:#ef444426}.option-btn:disabled{cursor:default}.feedback-box{border:1px solid var(--card-border);background:#0f172ab3;border-radius:1rem;margin-top:1.5rem;padding:1.5rem;animation:.5s fadeIn}.feedback-status{align-items:center;gap:.5rem;margin-bottom:1rem;font-size:1.1rem;font-weight:700;display:flex}.status-correct{color:#10b981}.status-incorrect{color:#ef4444}.explanation-content{color:var(--text-muted);font-size:.95rem;line-height:1.6}.explanation-content p{margin-bottom:.75rem}.explanation-content strong{color:var(--text-main)}.loader-container{justify-content:center;align-items:center;height:200px;display:flex}.spinner{border:3px solid #ffffff1a;border-top-color:var(--primary-color);border-radius:50%;width:40px;height:40px;animation:1s ease-in-out infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.hidden{display:none!important}.mt-2{margin-top:2rem}.text-center{text-align:center}@media (width<=480px){#app{padding:1rem}.glass-card{padding:1.5rem}h1{font-size:1.75rem}.option-btn{padding:1rem 1.25rem;font-size:1rem}}