body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 30px;
}

.container {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 30px;
    margin-bottom: 30px;
}

.start-screen p {
    text-align: center;
    margin-bottom: 20px;
    font-size: 18px;
    color: #555;
}

.start-btn {
    display: block;
    width: 250px;
    margin: 30px auto;
    background-color: #3498db;
    color: white;
    border: none;
    padding: 15px 25px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 18px;
    font-weight: 500;
    transition: background-color 0.2s;
    text-align: center;
}

.start-btn:hover {
    background-color: #2980b9;
}

.question-container {
    display: none;
    margin-bottom: 20px;
}

.question {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 15px;
    color: #2c3e50;
}

.options {
    display: grid;
    gap: 10px;
}

.option-btn {
    background-color: #f1f5f9;
    border: 1px solid #ddd;
    padding: 12px 15px;
    text-align: left;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.option-btn:hover {
    background-color: #e2e8f0;
}

.selected {
    background-color: #ddeeff;
    border-color: #3498db;
}

.correct {
    background-color: #d4edda;
    border-color: #28a745;
}

.incorrect {
    background-color: #f8d7da;
    border-color: #dc3545;
}

.nav-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.nav-btn {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.2s;
}

.nav-btn:hover {
    background-color: #2980b9;
}

.nav-btn:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

.submit-btn {
    background-color: #27ae60;
}

.submit-btn:hover {
    background-color: #219653;
}

.results-container {
    display: none;
}

.results-header {
    margin-bottom: 20px;
    text-align: center;
}

.score {
    font-size: 24px;
    font-weight: bold;
    color: #2c3e50;
    margin-bottom: 10px;
}

.review-item {
    margin-bottom: 20px;
    padding: 15px;
    border-radius: 5px;
}

.review-item.correct {
    background-color: rgba(212, 237, 218, 0.5);
}

.review-item.incorrect {
    background-color: rgba(248, 215, 218, 0.5);
}

.review-question {
    font-weight: 600;
    margin-bottom: 10px;
}

.review-answer {
    margin-bottom: 10px;
}

.explanation {
    background-color: #f8f9fa;
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
    font-size: 14px;
}

.category-scores {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin: 15px 0;
}

.category-score {
    background-color: #f1f5f9;
    padding: 8px 15px;
    border-radius: 5px;
    font-size: 14px;
    font-weight: 500;
}

.share-container {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 5px;
    margin: 20px 0;
    text-align: center;
}

.share-container h3 {
    margin-top: 0;
    margin-bottom: 15px;
    color: #2c3e50;
}

.share-input-container {
    display: flex;
    margin-bottom: 15px;
}

.share-text {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px 0 0 5px;
    font-size: 14px;
}

.share-btn {
    background-color: #3498db;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 0 5px 5px 0;
    cursor: pointer;
    font-size: 14px;
}

.social-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.social-btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 5px;
    color: white;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.social-btn:hover {
    opacity: 0.9;
}

.twitter-btn {
    background-color: #000000;
}

.try-again-btn {
    display: block;
    width: 200px;
    margin: 30px auto 0;
    background-color: #3498db;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    text-align: center;
}

/* Category selection styles */
.mode-option {
    text-align: center;
    margin: 10px 0;
    font-size: 16px;
    color: #666;
}

.select-category-btn {
    background-color: #2ecc71;
}

.select-category-btn:hover {
    background-color: #27ae60;
}

.category-selection-screen {
    display: none;
}

.category-options {
    margin: 20px 0;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.category-option {
    margin-bottom: 10px;
}

.category-btn {
    display: block;
    width: 100%;
    background-color: #f8f9fa;
    border: 1px solid #ddd;
    padding: 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    transition: all 0.2s;
}

.category-btn:hover {
    background-color: #e2e8f0;
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.category-selection-buttons {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 20px;
}

.back-btn {
    display: block;
    width: 200px;
    margin: 0 auto;
    background-color: #95a5a6;
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    text-align: center;
    transition: background-color 0.2s;
}

.back-btn:hover {
    background-color: #7f8c8d;
}