:root{--primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);--success-gradient: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);--error-gradient: linear-gradient(135deg, #eb3349 0%, #f45c43 100%);--bg-dark: #0a0a0f;--bg-card: rgba(255, 255, 255, .05);--bg-card-hover: rgba(255, 255, 255, .1);--text-primary: #ffffff;--text-secondary: rgba(255, 255, 255, .7);--text-muted: rgba(255, 255, 255, .5);--border-color: rgba(255, 255, 255, .1);--border-glow: rgba(102, 126, 234, .5);--spacing-xs: .25rem;--spacing-sm: .5rem;--spacing-md: 1rem;--spacing-lg: 1.5rem;--spacing-xl: 2rem;--spacing-2xl: 3rem;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 16px;--radius-xl: 24px;--transition-fast: .15s ease;--transition-normal: .3s ease;--transition-slow: .5s ease}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg-dark);color:var(--text-primary);min-height:100vh;line-height:1.6}body:before{content:"";position:fixed;inset:0;background:radial-gradient(ellipse at 20% 20%,rgba(102,126,234,.15) 0%,transparent 50%),radial-gradient(ellipse at 80% 80%,rgba(118,75,162,.15) 0%,transparent 50%);pointer-events:none;z-index:-1}#root{min-height:100vh;display:flex;flex-direction:column}.container{max-width:800px;margin:0 auto;padding:var(--spacing-lg)}.card{background:var(--bg-card);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border:1px solid var(--border-color);border-radius:var(--radius-lg);padding:var(--spacing-xl);transition:all var(--transition-normal)}.card:hover{background:var(--bg-card-hover);border-color:var(--border-glow);box-shadow:0 8px 32px #667eea26}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--spacing-sm);padding:var(--spacing-md) var(--spacing-xl);border:none;border-radius:var(--radius-md);font-size:1rem;font-weight:600;cursor:pointer;transition:all var(--transition-normal);text-decoration:none}.btn-primary{background:var(--primary-gradient);color:var(--text-primary);box-shadow:0 4px 15px #667eea66}.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 25px #667eea80}.btn-secondary{background:var(--bg-card);color:var(--text-primary);border:1px solid var(--border-color)}.btn-secondary:hover{background:var(--bg-card-hover);border-color:var(--border-glow)}.btn-lg{padding:var(--spacing-lg) var(--spacing-2xl);font-size:1.125rem}h1,h2,h3{font-weight:700;letter-spacing:-.02em}h1{font-size:2.5rem;background:var(--primary-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}h2{font-size:1.75rem;color:var(--text-primary)}.progress-bar{width:100%;height:8px;background:var(--bg-card);border-radius:4px;overflow:hidden}.progress-bar-fill{height:100%;background:var(--primary-gradient);border-radius:4px;transition:width var(--transition-normal)}.option-btn{width:100%;padding:var(--spacing-lg);background:var(--bg-card);border:2px solid var(--border-color);border-radius:var(--radius-md);color:var(--text-primary);font-size:1rem;text-align:left;cursor:pointer;transition:all var(--transition-normal)}.option-btn:hover{background:var(--bg-card-hover);border-color:var(--border-glow);transform:translate(8px)}.option-btn.selected{border-color:#667eea;background:#667eea33}.option-btn.correct{border-color:#38ef7d;background:#38ef7d33}.option-btn.incorrect{border-color:#f45c43;background:#f45c4333}@keyframes fadeIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.5}}@keyframes slideIn{0%{opacity:0;transform:translate(-20px)}to{opacity:1;transform:translate(0)}}.animate-fadeIn{animation:fadeIn .5s ease forwards}.animate-slideIn{animation:slideIn .3s ease forwards}.home{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;text-align:center;padding:var(--spacing-xl)}.home-icon{font-size:4rem;margin-bottom:var(--spacing-lg)}.home h1{margin-bottom:var(--spacing-md)}.home-description{color:var(--text-secondary);font-size:1.125rem;max-width:500px;margin-bottom:var(--spacing-2xl)}.home-features{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--spacing-lg);margin-bottom:var(--spacing-2xl);width:100%;max-width:600px}.feature-item{padding:var(--spacing-lg);background:var(--bg-card);border-radius:var(--radius-md);border:1px solid var(--border-color)}.feature-item-icon{font-size:1.5rem;margin-bottom:var(--spacing-sm)}.feature-item-text{font-size:.875rem;color:var(--text-secondary)}.quiz-container{min-height:100vh;padding:var(--spacing-xl)}.quiz-header{margin-bottom:var(--spacing-xl)}.quiz-progress{display:flex;align-items:center;gap:var(--spacing-md);margin-bottom:var(--spacing-md)}.quiz-progress-text{color:var(--text-secondary);font-size:.875rem;white-space:nowrap}.quiz-question{font-size:1.25rem;margin-bottom:var(--spacing-xl);line-height:1.8}.quiz-options{display:flex;flex-direction:column;gap:var(--spacing-md);margin-bottom:var(--spacing-xl)}.quiz-actions{display:flex;justify-content:flex-end}.result{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;padding:var(--spacing-xl);text-align:center}.result-score{font-size:6rem;font-weight:800;background:var(--primary-gradient);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:var(--spacing-md)}.result-message{font-size:1.5rem;margin-bottom:var(--spacing-lg)}.result-stats{display:flex;gap:var(--spacing-xl);margin-bottom:var(--spacing-2xl)}.result-stat{text-align:center}.result-stat-value{font-size:2rem;font-weight:700;color:var(--text-primary)}.result-stat-label{font-size:.875rem;color:var(--text-muted)}.result-details{width:100%;max-width:600px;margin-bottom:var(--spacing-2xl)}.result-item{background:var(--bg-card);border-radius:var(--radius-md);padding:var(--spacing-lg);margin-bottom:var(--spacing-md);text-align:left;border:1px solid var(--border-color)}.result-item.correct{border-left:4px solid #38ef7d}.result-item.incorrect{border-left:4px solid #f45c43}.result-item-question{font-weight:600;margin-bottom:var(--spacing-sm)}.result-item-explanation{font-size:.875rem;color:var(--text-secondary)}.loading{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;gap:var(--spacing-lg)}.loading-spinner{width:48px;height:48px;border:4px solid var(--border-color);border-top-color:#667eea;border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}@media(max-width:640px){h1{font-size:2rem}.home-features{grid-template-columns:1fr}.result-stats{flex-direction:column;gap:var(--spacing-lg)}.result-score{font-size:4rem}}