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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    overflow-x: hidden;
}

.app-container {
    position: relative;
    min-height: 100vh;
    width: 100%;
}

.background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: 0;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.6) 0%, rgba(0, 0, 0, 0.8) 100%);
    z-index: 1;
}

.content {
    position: relative;
    z-index: 2;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    padding: 20px 16px;
    text-align: center;
    color: white;
}

.header h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.user-info {
    margin-bottom: 16px;
}

.greeting {
    font-size: 16px;
    opacity: 0.9;
}

#userName {
    font-weight: 600;
    color: #FFD700;
}

.progress-bar {
    max-width: 300px;
    margin: 0 auto;
}

.progress-text {
    font-size: 14px;
    margin-bottom: 8px;
    opacity: 0.9;
}

.progress-track {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #FFD700, #FFA500);
    border-radius: 3px;
    transition: width 0.3s ease;
}

.quiz-container {
    flex: 1;
    padding: 16px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.question-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    max-width: 400px;
    margin: 0 auto;
    width: 100%;
}

.question-image {
    width: 100%;
    height: 180px;
    background-size: cover;
    background-position: center;
    border-radius: 12px;
    margin-bottom: 16px;
    background-color: #f0f0f0;
}

.question-content {
    text-align: center;
}

.question-text {
    font-size: 18px;
    font-weight: 600;
    color: #333;
    margin-bottom: 20px;
    line-height: 1.4;
}

.answers {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.answer-button {
    padding: 14px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    background: white;
    color: #333;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: left;
}

.answer-button:hover:not(:disabled) {
    border-color: #667eea;
    background: #f8f9ff;
}

.answer-button:disabled {
    cursor: not-allowed;
}

.answer-button.correct {
    border-color: #4CAF50;
    background: #4CAF50;
    color: white;
}

.answer-button.incorrect {
    border-color: #f44336;
    background: #f44336;
    color: white;
}

.fact-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    max-width: 400px;
    margin: 0 auto;
    text-align: center;
}

.fact-card h3 {
    font-size: 20px;
    color: #667eea;
    margin-bottom: 12px;
}

.fact-card p {
    font-size: 16px;
    color: #333;
    line-height: 1.5;
    margin-bottom: 20px;
}

.next-button {
    padding: 14px 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.next-button:hover {
    transform: scale(1.05);
}

.result-card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 16px;
    padding: 32px 24px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    max-width: 400px;
    margin: 0 auto;
    text-align: center;
}

.result-card h2 {
    font-size: 24px;
    color: #333;
    margin-bottom: 16px;
    line-height: 1.3;
}

.score {
    font-size: 32px;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 16px;
}

.bonus-result {
    font-size: 14px;
    color: #666;
    margin-bottom: 24px;
    padding: 12px;
    background: #f8f9ff;
    border-radius: 8px;
}

.restart-button {
    padding: 14px 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.restart-button:hover {
    transform: scale(1.05);
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 20px;
    }
    
    .question-text {
        font-size: 16px;
    }
    
    .answer-button {
        font-size: 14px;
        padding: 12px 16px;
    }
    
    .question-image {
        height: 150px;
    }
}

@media (min-width: 768px) {
    .question-card,
    .fact-card,
    .result-card {
        max-width: 500px;
    }
}