:root {
    --primary-color: #4a6cfa;
    --secondary-color: #f3f4f6;
    --text-color: #333;
    --light-text: #666;
    --border-color: #e5e7eb;
    --hover-color: #3a5ce8;
    --section-bg: #f9fafb;
  }
  
  /* * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Helvetica Neue', Arial, sans-serif;
  }
   */
  /* body {
    color: var(--text-color);
    line-height: 1.6;
    background-color: #fff;
  }
   */
  /* .container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
  } */
  
  /* header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
  }
  
  .header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    padding: 0 20px;
    max-width: 1200px;
    margin: 0 auto;
  }
   */
  /* .logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
  }
  
  .nav-links {
    display: flex;
    gap: 24px;
  }
  
  .nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
  }
  
  .nav-links a:hover {
    color: var(--primary-color);
  }
   */
  .article-header {
    padding: 40px 0 30px;
    border-bottom: 1px solid var(--border-color);
  }
  
  .article-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    line-height: 1.2;
  }
  
  .article-metadata {
    display: flex;
    align-items: center;
    color: var(--light-text);
    font-size: 0.9rem;
    margin-bottom: 24px;
  }
  
  .article-date {
    margin-right: 24px;
  }
  
  .article-category {
    display: inline-block;
    background-color: var(--secondary-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-weight: 500;
  }
  
  .article-image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    border-radius: 8px;
    margin: 30px 0;
    background-color: var(--secondary-color);
  }
  
  .article-content {
    padding: 30px 0 60px;
  }
  
  .article-content p {
    margin-bottom: 24px;
    font-size: 1.1rem;
  }
  
  .article-content h2 {
    font-size: 1.8rem;
    margin: 40px 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--secondary-color);
  }
  
  .article-content h3 {
    font-size: 1.4rem;
    margin: 30px 0 16px;
  }
  
  .article-content ul, .article-content ol {
    margin-bottom: 24px;
    padding-left: 20px;
  }
  
  .article-content li {
    margin-bottom: 10px;
  }
  
  .article-content strong {
    font-weight: 600;
  }
  
  .info-box {
    background-color: var(--section-bg);
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    border-left: 4px solid var(--primary-color);
  }
  
  .info-box h3 {
    margin-top: 0;
    color: var(--primary-color);
  }
  
  .tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 30px 0;
  }
  
  .tag {
    background-color: var(--secondary-color);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--light-text);
  }
  
  .related-articles {
    background-color: var(--section-bg);
    padding: 40px 0;
    margin-top: 60px;
  }
  
  .related-articles h2 {
    text-align: center;
    margin-bottom: 30px;
  }
  
  .article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }
  
  .article-card {
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
  }
  
  .article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  }
  
  .card-image {
    height: 160px;
    background-color: var(--secondary-color);
  }
  
  .card-content {
    padding: 16px;
  }
  
  .card-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
  }
  
  .card-excerpt {
    font-size: 0.9rem;
    color: var(--light-text);
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  
  footer {
    background-color: #2d3748;
    color: white;
    padding: 40px 0;
  }
  
  .footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
  }
  
  .footer-column h3 {
    font-size: 1.2rem;
    margin-bottom: 20px;
  }
  
  .footer-links {
    list-style: none;
  }
  
  .footer-links li {
    margin-bottom: 10px;
  }
  
  .footer-links a {
    color: #cbd5e0;
    text-decoration: none;
    transition: color 0.2s;
  }
  
  .footer-links a:hover {
    color: white;
  }
  
  .footer-bottom {
    text-align: center;
    padding-top: 40px;
    color: #cbd5e0;
    font-size: 0.9rem;
  }
  
  /* Responsive styles */
  @media (max-width: 768px) {
    .article-title {
      font-size: 2rem;
    }
    
    .article-image {
      height: 250px;
    }
    
    .nav-links {
      display: none;
    }
  }

  .table-of-contents {
    background-color: var(--section-bg);
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
  }

  .table-of-contents h3 {
    margin-top: 0;
    margin-bottom: 16px;
  }

  .table-of-contents ol {
    padding-left: 20px;
  }

  .table-of-contents li {
    margin-bottom: 8px;
  }

  .table-of-contents a {
    color: var(--primary-color);
    text-decoration: none;
  }

  .table-of-contents a:hover {
    text-decoration: underline;
  }

  .conclusion {
    background-color: var(--section-bg);
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    border-left: 4px solid #4CAF50;
  }

  /* ====== ブログセクション ====== */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
}

.blog-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease;
}

.blog-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.12);
}

.blog-card-link {
    display: block;
    text-decoration: none;
    color: inherit;
    height: 100%;
}

.blog-image {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.blog-image-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.blog-image-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #bdc3c7;
    color: white;
    font-weight: 500;
}

.blog-date {
    position: absolute;
    top: 15px;
    left: 15px;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.9rem;
}

.blog-content {
    padding: 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.blog-title {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: #2c3e50;
    font-weight: 600;
}

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

.blog-category span {
    background-color: #f0f2f5;
    color: #2c3e50;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    display: inline-block;
}

.blog-desc {
    color: #555;
    font-size: 0.95rem;
    margin-bottom: 15px;
    flex: 1;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.blog-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 15px;
}

.blog-tag {
    background-color: #f0f2f5;
    color: #2c3e50;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
    border: 1px solid #e0e6ed;
}

.blog-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    border-top: 1px solid #ecf0f1;
    padding-top: 15px;
}

.blog-more {
    color: #3498db;
    font-weight: 600;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
}

.blog-more::after {
    content: '→';
    margin-left: 5px;
    transition: transform 0.3s ease;
}

.blog-card:hover .blog-more::after {
    transform: translateX(3px);
}

.blog-edit-btn {
    background-color: #f1c40f;
    color: white;
    border: none;
    padding: 6px 12px;
    border-radius: 5px;
    font-weight: 600;
    font-size: 0.85rem;
    transition: background-color 0.3s ease;
}

.blog-edit-btn:hover {
    background-color: #e67e22;
}

/* ページネーション */
.pagination-container {
    margin-top: 40px;
    display: flex;
    justify-content: center;
}

/* 投稿がない場合のメッセージ */
.no-posts {
    background: white;
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    margin: 30px 0;
    color: #7f8c8d;
    font-size: 1.1rem;
}

/* レスポンシブスタイル */
@media (max-width: 768px) {
    .blog-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    }
}

@media (max-width: 480px) {
    .blog-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
}