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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.header {
    background: linear-gradient(135deg, #232F3E, #4A90E2);
    color: white;
    padding: 1rem;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.progress {
    font-size: 0.9rem;
    opacity: 0.9;
}

.main {
    max-width: 800px;
    margin: 0 auto;
    padding: 1rem;
}

.loading {
    text-align: center;
    padding: 2rem;
    font-size: 1.1rem;
}

.progress-bar-container {
    width: 100%;
    max-width: 300px;
    height: 8px;
    background-color: #e0e0e0;
    border-radius: 4px;
    margin: 1rem auto;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, #4A90E2, #4CAF50);
    border-radius: 4px;
    transition: width 0.2s ease;
}

.loading-status {
    font-size: 0.9rem;
    color: #666;
    margin-top: 0.5rem;
}

.quiz-container {
    background: white;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
}

.question-section {
    margin-bottom: 2rem;
}

.question-section h2 {
    color: #232F3E;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.question-content {
    font-size: 1.1rem;
    line-height: 1.7;
}

.question-content img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 1rem 0;
}

.question-content a {
    color: #4A90E2;
    text-decoration: none;
}

.question-content a:hover {
    text-decoration: underline;
}

.choices {
    margin-bottom: 1.5rem;
}

.choice {
    display: block;
    width: 100%;
    padding: 1rem;
    margin-bottom: 0.5rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    font-size: 1rem;
}

.choice:hover {
    border-color: #4A90E2;
    background-color: #f8f9ff;
}

.choice.selected {
    border-color: #4A90E2;
    background-color: #e3f2fd;
}

.choice.correct {
    border-color: #4CAF50;
    background-color: #e8f5e8;
}

.choice.incorrect {
    border-color: #f44336;
    background-color: #ffebee;
}

.submit-btn, .next-btn, .restart-btn {
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.submit-btn {
    background-color: #4A90E2;
    color: white;
}

.submit-btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

.submit-btn:not(:disabled):hover {
    background-color: #357abd;
}

.next-btn {
    background-color: #4CAF50;
    color: white;
}

.next-btn:hover {
    background-color: #45a049;
}

.restart-btn {
    background-color: #FF9800;
    color: white;
}

.restart-btn:hover {
    background-color: #f57c00;
}

.result-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid #e0e0e0;
}

.result-message {
    font-size: 1.2rem;
    font-weight: bold;
    margin-bottom: 1rem;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
}

.result-message.correct {
    background-color: #e8f5e8;
    color: #2e7d32;
}

.result-message.incorrect {
    background-color: #ffebee;
    color: #c62828;
}

.explanation {
    background-color: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border-left: 4px solid #4A90E2;
}

.explanation h3 {
    color: #232F3E;
    margin-bottom: 1rem;
}

.explanation img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 1rem 0;
}

.explanation a {
    color: #4A90E2;
    text-decoration: none;
}

.explanation a:hover {
    text-decoration: underline;
}

.complete-section {
    text-align: center;
    background: white;
    border-radius: 12px;
    padding: 3rem 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.complete-section h2 {
    color: #4CAF50;
    margin-bottom: 1rem;
    font-size: 2rem;
}

.complete-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: #666;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .main {
        padding: 0.5rem;
    }
    
    .quiz-container {
        padding: 1rem;
    }
    
    .header h1 {
        font-size: 1.3rem;
    }
    
    .progress {
        font-size: 0.8rem;
    }
}


/* マークダウン要素のスタイル */
.explanation h4,
.explanation h5,
.explanation h6,
.question-content h4,
.question-content h5,
.question-content h6 {
    color: #232F3E;
    margin: 1rem 0 0.5rem 0;
}

.explanation h4 { font-size: 1.1rem; }
.explanation h5 { font-size: 1rem; }
.explanation h6 { font-size: 0.95rem; }

.explanation ul,
.question-content ul {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
}

.explanation li,
.question-content li {
    margin: 0.3rem 0;
}

.explanation code,
.question-content code {
    background-color: #f0f0f0;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9em;
}

.explanation pre,
.question-content pre {
    background-color: #2d2d2d;
    color: #f8f8f2;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem 0;
}

.explanation pre code,
.question-content pre code {
    background-color: transparent;
    padding: 0;
    color: inherit;
}

.explanation strong,
.question-content strong {
    color: #232F3E;
    font-weight: 600;
}

.explanation em,
.question-content em {
    font-style: italic;
}

.explanation hr,
.question-content hr {
    border: none;
    border-top: 1px solid #e0e0e0;
    margin: 1rem 0;
}

.explanation p,
.question-content p {
    margin: 0.5rem 0;
}