/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.site-header {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    padding: 2rem 0;
    text-align: center;
    color: white;
}

.site-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.site-description {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Main content */
.main-content {
    padding: 3rem 0;
    flex: 1;
}

/* Quiz container */
.quiz-container {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    max-width: 800px;
    margin: 0 auto;
}

.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 3rem 2rem;
    text-align: center;
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-section p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Level selection */
.level-selection {
    padding: 3rem 2rem;
    text-align: center;
}

.level-selection h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: #333;
}

.level-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.level-btn {
    background: white;
    border: 2px solid #e0e6ed;
    border-radius: 15px;
    padding: 2rem 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.level-btn:hover {
    border-color: #667eea;
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.15);
}

.level-btn h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #333;
}

.level-btn p {
    color: #666;
    margin-bottom: 0.5rem;
}

.level-btn p:last-child {
    font-weight: 500;
    color: #667eea;
}

/* Quiz section */
.quiz-section {
    padding: 2rem;
}

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

.quiz-header h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: #333;
}

.quiz-progress {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.progress-bar {
    width: 200px;
    height: 8px;
    background: #e0e6ed;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    transition: width 0.3s ease;
    width: 10%;
}

/* Question container */
.question-container {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.question-category {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    text-transform: uppercase;
}

.question-text {
    font-size: 1.3rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 2rem;
    line-height: 1.5;
}

.options-container {
    margin-bottom: 2rem;
}

.option {
    background: white;
    border: 2px solid #e0e6ed;
    border-radius: 10px;
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.option:hover {
    border-color: #667eea;
    background: #f0f4ff;
}

.option.selected {
    border-color: #667eea;
    background: #667eea;
    color: white;
}

.option-letter {
    background: #e0e6ed;
    color: #666;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.option.selected .option-letter {
    background: white;
    color: #667eea;
}

.option-text {
    flex: 1;
}

/* Buttons */
.submit-btn, .next-btn, .restart-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    width: 100%;
}

.submit-btn:hover, .next-btn:hover, .restart-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.submit-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Answer feedback */
.answer-feedback {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
}

.feedback-header {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.feedback-header.correct {
    color: #28a745;
}

.feedback-header.incorrect {
    color: #dc3545;
}

.feedback-explanation {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.feedback-link {
    margin-bottom: 2rem;
}

.feedback-link a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.feedback-link a:hover {
    text-decoration: underline;
}

/* Quiz results */
.quiz-results {
    text-align: center;
    padding: 2rem;
}

.quiz-results h2 {
    font-size: 2rem;
    color: #333;
    margin-bottom: 2rem;
}

.score-display {
    font-size: 3rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 2rem;
}

.results-breakdown {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    text-align: left;
}

.category-score {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid #e0e6ed;
}

.category-score:last-child {
    border-bottom: none;
}

/* Footer */
.site-footer {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: auto;
}

/* Responsive design */
@media (max-width: 768px) {
    .site-title {
        font-size: 2rem;
    }
    
    .hero-section h1 {
        font-size: 2rem;
    }
    
    .level-buttons {
        grid-template-columns: 1fr;
    }
    
    .quiz-progress {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .progress-bar {
        width: 100%;
    }
    
    .quiz-container {
        margin: 1rem;
    }
}