* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 50%, #fecfef 100%);
    min-height: 100vh;
    color: white;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

.back-btn {
    color: white;
    text-decoration: none;
    font-size: 1.2rem;
    position: absolute;
    top: 2rem;
    left: 2rem;
}

.stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 1rem;
    border-radius: 10px;
    backdrop-filter: blur(10px);
}

.stat {
    text-align: center;
}

.label {
    display: block;
    font-size: 0.9rem;
    opacity: 0.8;
}

.stat span:last-child {
    font-size: 1.5rem;
    font-weight: bold;
}

.question-card {
    background: white;
    border-radius: 20px;
    padding: 3rem;
    margin-bottom: 2rem;
    color: #333;
    min-height: 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

.question-text {
    font-size: 1.4rem;
    line-height: 1.6;
    text-align: center;
    margin-bottom: 2rem;
    font-weight: 500;
}

.answer-buttons {
    display: flex;
    gap: 2rem;
    justify-content: center;
}

.answer-btn {
    padding: 1.5rem 3rem;
    font-size: 1.2rem;
    font-weight: bold;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    min-width: 150px;
}

.true-btn {
    background: linear-gradient(135deg, #4CAF50, #45a049);
    color: white;
}

.true-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.4);
}

.false-btn {
    background: linear-gradient(135deg, #f44336, #da190b);
    color: white;
}

.false-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(244, 67, 54, 0.4);
}

.answer-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.feedback {
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.feedback-result {
    font-size: 2rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.feedback-result.correct {
    color: #4CAF50;
}

.feedback-result.incorrect {
    color: #f44336;
}

.feedback-explanation {
    font-size: 1.1rem;
    line-height: 1.5;
    margin-bottom: 2rem;
    padding: 1rem;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #007bff;
}

.next-btn {
    background: #007bff;
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 10px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.next-btn:hover {
    background: #0056b3;
}

.controls {
    text-align: center;
    margin-bottom: 2rem;
}

.controls button {
    background: #FF6B35;
    color: white;
    border: none;
    padding: 1rem 2rem;
    margin: 0.5rem;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.controls button:hover {
    background: #e55a2b;
}

.results {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    backdrop-filter: blur(10px);
}

.final-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 2rem;
}

.final-stat {
    text-align: center;
}

.value {
    display: block;
    font-size: 3rem;
    font-weight: bold;
    color: #FFD700;
}

.unit {
    font-size: 1rem;
    opacity: 0.8;
}

.timer-warning {
    color: #ff4444 !important;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.question-card.correct {
    border: 3px solid #4CAF50;
    background: linear-gradient(135deg, #e8f5e8, #ffffff);
}

.question-card.incorrect {
    border: 3px solid #f44336;
    background: linear-gradient(135deg, #ffeaea, #ffffff);
}

@media (max-width: 768px) {
    .stats, .final-stats {
        flex-direction: column;
        gap: 1rem;
    }
    
    .answer-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .question-card {
        padding: 2rem;
        min-height: 350px;
    }
    
    .question-text {
        font-size: 1.2rem;
    }
}