:root {
    --brand-red: #d9333f;
    --text-main: #333333;
    --text-light: #555555;
    --bg-body: #f5f7fa;
    --bg-card: #ffffff;
    --border-color: #e0e0e0;
}

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

body {
    font-family: 'Noto Sans JP', sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.8;
    padding: 40px 20px;
}

a {
    color: var(--brand-red);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-card);
    padding: 60px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    border-top: 5px solid var(--brand-red);
}

.header {
    text-align: center;
    margin-bottom: 50px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.header h1 {
    font-size: 1.8rem;
    color: var(--text-main);
    margin-bottom: 10px;
}

.header p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.chapter {
    margin-bottom: 40px;
}

.chapter-title {
    font-size: 1.4rem;
    color: var(--text-main);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
}

.chapter-title::before {
    content: '';
    display: inline-block;
    width: 4px;
    height: 20px;
    background-color: var(--brand-red);
    margin-right: 12px;
}

.article {
    margin-bottom: 30px;
}

.article-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-main);
}

.article-content {
    padding-left: 20px;
    color: var(--text-light);
    font-size: 0.95rem;
}

.article-content p {
    margin-bottom: 10px;
}

.article-list {
    list-style: none;
    margin-top: 10px;
    margin-bottom: 15px;
}

.article-list li {
    position: relative;
    padding-left: 24px;
    margin-bottom: 8px;
}

.article-list li::before {
    content: '(' attr(data-num) ')';
    position: absolute;
    left: 0;
    color: var(--text-light);
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    font-weight: 500;
}

.back-link::before {
    content: '← ';
}

@media (max-width: 600px) {
    .container {
        padding: 30px 20px;
    }
    .header h1 {
        font-size: 1.5rem;
    }
}