body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f5f5; /* 背景を明るい灰色に */
  }
  
  .App {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
  }
  
  /* メインヘッダー */
  .main-header {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 12px;
  }

  /* タイトルヘッダー */
  .title-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin-bottom: 8px;
    min-height: 40px;
    padding: 4px 0;
  }

  .title-left {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    min-height: 30px;
  }

  .title-right {
    display: flex;
    gap: 8px;
    align-items: center;
  }

  #header-links-container {
    display: flex;
    gap: 8px;
    align-items: center;
    max-width: 600px;
    overflow: hidden;
  }

  .header-link {
    background-color: #e0e0e0;
    color: black;
    font-weight: bold;
    font-size: 16px;
    text-decoration: none;
    padding: 8px 12px;
    border-radius: 5px;
    transition: background-color 0.3s, transform 0.2s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    white-space: nowrap;
    min-width: 60px;
    flex-shrink: 0;
  }

  .header-link:hover {
    background-color: #d0d0d0;
    transform: scale(1.05);
  }


  /* ヘッダーリンク編集モード */
  .header-edit-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
    min-height: 400px;
  }

  .header-links-list-container {
    flex-grow: 1;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 15px;
    background-color: #f9f9f9;
    max-height: 300px;
    overflow-y: auto;
  }

  #modal-header-link-list {
    list-style: none;
    padding: 0;
    margin: 0;
  }

  #modal-header-link-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    border-bottom: 1px solid #ddd;
    cursor: move;
    background-color: #fff;
    border-radius: 6px;
    margin-bottom: 8px;
    border: 1px solid #e0e0e0;
  }

  .header-link-info {
    flex-grow: 1;
    margin-right: 10px;
  }

  .header-link-title {
    font-weight: bold;
    color: #333;
    margin-bottom: 4px;
  }

  .header-link-url {
    font-size: 12px;
    color: #666;
    word-break: break-all;
  }

  .add-header-link-form {
    background-color: #f0f8ff;
    padding: 15px;
    border-radius: 8px;
    border: 2px solid #4a90e2;
  }

  .title-left h1 {
    font-family: 'Comic Sans MS', 'Arial', sans-serif;
    font-size: 22px;
    font-weight: bold;
    margin: 0;
    background: linear-gradient(90deg, #333, #666);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 1px;
    cursor: pointer;
    user-select: none;
    line-height: 1.3;
    padding: 2px 0;
    display: flex;
    align-items: center;
  }

  .title-input {
    display: none;
    font-size: 28px;
    font-weight: bold;
    font-family: 'Comic Sans MS', 'Arial', sans-serif;
    border: 2px solid #666;
    border-radius: 5px;
    padding: 5px 10px;
    background: transparent;
    color: #333;
    letter-spacing: 1.5px;
    width: 100%;
    box-sizing: border-box;
    resize: none;
    word-wrap: break-word;
    line-height: 1.2;
  }

  .title-input:focus {
    outline: none;
    border-color: #333;
  }

  /* ヘッダーナビゲーション */
  .header-navigation {
    display: flex;
    flex-direction: column;
    gap: 4px;
  }

  .fixed-buttons-group {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
  }

  .dynamic-buttons-group {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
  }

  #project-links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  /* メインコンテンツエリア */
  #main-content {
    margin-top: 10px;
  }

.navigation-link {
    text-decoration: none;
    color: #fff;
    background-color: #666;
    font-size: 12px;
    font-weight: bold;
    padding: 6px 14px;
    border-radius: 6px;
    transition: all 0.3s ease;
    text-align: center;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    min-width: 70px;
    height: 26px;
    box-sizing: border-box;
    position: relative;
    border: 2px solid transparent;
}

.navigation-link:hover {
    background-color: #444;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.navigation-link.active {
    background-color: #333;
    border: 2px solid #999;
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.3);
    transform: translateY(-1px);
}

.navigation-link.active::after {
    content: "●";
    position: absolute;
    top: -5px;
    right: -5px;
    color: #bbb;
    font-size: 12px;
    background-color: #333;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid #999;
}

/* 内部リンク用のスタイル */
.internal-link {
    background-color: #6b8ca3; /* 落ち着いたブルーグレー */
    color: white;
}

.internal-link:hover {
    background-color: #5a7a94; /* ホバー時のダークブルーグレー */
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(107, 140, 163, 0.3);
}

.internal-link.active {
    background-color: #4d6b7d; /* アクティブ時のより落ち着いた色 */
    border-color: #6b8ca3;
    box-shadow: 0 0 8px rgba(107, 140, 163, 0.4);
}

.internal-link.active::after {
    background-color: #4d6b7d;
    border-color: #6b8ca3;
}


  .section-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
  }

  .section.dragging {
    opacity: 0.5;
    transform: scale(1.05);
    z-index: 1000;
    position: relative;
  }

  .section.drag-over {
    border: 2px dashed #4a90e2;
    background-color: #f0f8ff;
  }
  
  .section {
    background-color: #ffffff;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s, box-shadow 0.2s;
    position: relative;
    overflow: hidden;
    cursor: move;
  }
  
  /* 強化されたセクションスタイル */
  .enhanced-section {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border: 2px solid #e9ecef;
    border-radius: 12px;
    padding: 0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    overflow: hidden;
  }
  
  .enhanced-section:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
    border-color: #6c757d;
  }
  
  .enhanced-section[data-category="work"]:hover {
    border-color: #007bff;
  }
  
  .enhanced-section[data-category="social"]:hover {
    border-color: #28a745;
  }
  
  .enhanced-section[data-category="dev"]:hover {
    border-color: #dc3545;
  }
  
  .enhanced-section[data-category="entertainment"]:hover {
    border-color: #fd7e14;
  }
  
  .enhanced-section[data-category="news"]:hover {
    border-color: #6f42c1;
  }
  
  .enhanced-section[data-category="shopping"]:hover {
    border-color: #e83e8c;
  }
  
  /* コンパクトなセクションヘッダー */
  .section-header {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-bottom: 1px solid #dee2e6;
  }
  
  .section-title-area {
    flex-grow: 1;
  }
  
  .section-title-text {
    margin: 0 0 4px 0;
    font-size: 16px;
    font-weight: bold;
    color: #333;
    cursor: pointer;
    transition: color 0.2s;
    line-height: 1.4;
    padding: 2px 0;
    display: flex;
    align-items: center;
    min-height: 22px;
  }
  
  .section-title-text:hover {
    color: #007bff;
  }
  
  .section-subtitle {
    font-size: 11px;
    color: #6c757d;
    margin: 0;
    cursor: pointer;
    transition: color 0.2s;
    line-height: 1.3;
    padding: 1px 0;
    min-height: 14px;
    display: flex;
    align-items: center;
  }
  
  .section-subtitle:hover {
    color: #007bff;
  }
  
  .section-actions {
    display: flex;
    gap: 8px;
  }
  
  .action-btn {
    background: none;
    border: none;
    padding: 4px 6px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    transition: all 0.2s;
    opacity: 0.4;
    color: #cccccc;
  }
  
  .action-btn:hover {
    opacity: 0.7;
    background-color: rgba(0, 0, 0, 0.05);
    color: #999999;
  }
  
  .favorite-btn.active {
    opacity: 1;
    color: #ffc107;
  }
  
  /* コンパクトなリンクグリッド */
  .link-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 6px;
    padding: 12px;
  }
  
  /* インライン（1行）表示のリンク */
  .link-card.inline {
    grid-column: 1 / -1;
    max-width: 100%;
  }
  
  .link-card.inline .link-card-content {
    justify-content: flex-start;
    padding: 4px 8px;
    min-height: 24px;
  }
  
  .link-card.inline .link-title {
    font-size: 12px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  
  .link-card {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    transition: all 0.15s ease;
    overflow: visible;
    position: relative;
  }
  
  .link-actions {
    position: absolute;
    top: 2px;
    right: 2px;
    opacity: 0;
    transition: opacity 0.2s;
    z-index: 10;
    display: flex;
    gap: 2px;
  }
  
  /* ヘッダーリンク編集モーダル内の編集ボタンを常に表示 */
  #modal-header-link-list .link-actions {
    position: static;
    opacity: 1;
    margin-left: 10px;
  }
  
  .link-card:hover .link-actions {
    opacity: 1;
  }
  
  .link-actions button {
    background: #007bff;
    color: white;
    border: none;
    border-radius: 3px;
    padding: 2px 4px;
    font-size: 10px;
    cursor: pointer;
    transition: background-color 0.2s;
  }
  
  .link-actions button:hover {
    background: #0056b3;
  }
  
  .link-actions button:last-child {
    background: #dc3545;
  }
  
  .link-actions button:last-child:hover {
    background: #c82333;
  }
  
  /* 編集中のリンクカードのハイライト */
  .link-card.editing {
    border: 2px solid #007bff;
    background: linear-gradient(135deg, #e3f2fd 0%, #f0f8ff 100%);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.3);
    transform: scale(1.02);
  }
  
  .link-card.editing .link-actions {
    opacity: 1;
  }
  
  .link-card.editing::before {
    content: "編集中";
    position: absolute;
    top: -8px;
    left: 8px;
    background: #007bff;
    color: white;
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 3px;
    z-index: 20;
  }
  
  .link-card:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    border-color: #999;
  }
  
  .link-card-content {
    display: flex;
    align-items: center;
    padding: 4px 8px;
    text-decoration: none;
    color: inherit;
    min-height: 24px;
  }
  
  .link-favicon {
    font-size: 14px;
    margin-right: 8px;
    min-width: 16px;
    text-align: center;
    color: #666;
  }
  
  .link-info {
    flex-grow: 1;
    min-width: 0;
  }
  
  .link-title {
    font-weight: 500;
    color: #333;
    font-size: 13px;
    line-height: 1.2;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  
  .link-url {
    display: none; /* URLは非表示にしてよりコンパクトに */
  }
  
  .section:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 12px rgba(0, 0, 0, 0.15);
  }
  
  .section h2 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #333;
  }
  
  .section ul,
  .section p {
    font-size: 14px;
    color: #555;
    margin: 0;
  }
  
  .section ul li {
    word-wrap: break-word; /* テキストの折り返しを有効に */
    word-break: break-all; /* 長いリンクテキストを強制的に改行 */
    overflow-wrap: break-word; /* CSS3対応の折り返し */
  }
  
  .section-name-input {
    display: none;
    width: 100%;
    font-size: 16px;
    margin-top: 5px;
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 5px;
    line-height: 1.4;
    min-height: 20px;
    box-sizing: border-box;
  }
  
  .section-name-input:focus {
    display: block;
  }
  
  .section-subtitle-input {
    width: 100%;
    font-size: 11px;
    padding: 4px 6px;
    border: 1px solid #ccc;
    border-radius: 3px;
    margin-top: 2px;
    line-height: 1.3;
    min-height: 14px;
    box-sizing: border-box;
    background-color: #fff;
  }
  
  .section-subtitle-input:focus {
    outline: none;
    border-color: #007bff;
  }
  
  .modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    justify-content: center;
    align-items: center;
  }
  
  .modal-content {
    width: 700px;
    max-width: 95%;
    max-height: 90vh;
    background-color: #ffffff;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }
  
  .modal-content h3 {
    margin: 0;
    padding: 20px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-bottom: 1px solid #dee2e6;
    font-size: 18px;
    font-weight: bold;
    color: #333;
    text-align: center;
  }
  
  .modal-editing-info {
    background: linear-gradient(135deg, #e3f2fd 0%, #f0f8ff 100%);
    border: 1px solid #007bff;
    border-radius: 6px;
    padding: 10px;
    margin-bottom: 15px;
    font-size: 14px;
    color: #0056b3;
  }
  
  .modal-editing-info .editing-label {
    font-weight: bold;
    color: #007bff;
    margin-bottom: 5px;
  }
  
  .modal-editing-info .editing-details {
    font-size: 12px;
    color: #666;
  }
  
  /* 単一リンク編集モード */
  .single-edit-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
  
  .current-link-info {
    background: linear-gradient(135deg, #e8f5e8 0%, #f0f8f0 100%);
    border: 1px solid #28a745;
    border-radius: 8px;
    padding: 15px;
  }
  
  .info-label {
    font-weight: bold;
    color: #28a745;
    font-size: 16px;
    margin-bottom: 10px;
  }
  
  .info-details {
    font-size: 14px;
    color: #495057;
    line-height: 1.5;
  }
  
  .edit-form-container {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 20px;
  }
  
  .edit-form-container .form-row {
    margin-bottom: 15px;
  }
  
  .edit-form-container .form-options {
    margin-bottom: 20px;
  }
  
  .edit-form-container .form-buttons {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
  }
  
  #save-edit-btn {
    background-color: #28a745;
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
  }
  
  #save-edit-btn:hover {
    background-color: #218838;
  }
  
  .list-edit-container {
    display: block;
  }
  
  .modal-body {
    padding: 20px;
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
  
  .link-list-container {
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    background-color: #f8f9fa;
  }
  
  .add-link-form {
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 15px;
    background-color: #fff;
  }
  
  .form-row {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
  }
  
  .form-row input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font-size: 14px;
  }
  
  .form-options {
    margin-bottom: 15px;
  }
  
  .checkbox-container {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 14px;
    color: #333;
  }
  
  .checkbox-container input[type="checkbox"] {
    margin-right: 8px;
  }
  
  .form-buttons {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
  }
  
  .form-buttons button {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
  }
  
  #add-link-btn, #update-link-btn {
    background-color: #007bff;
    color: white;
  }
  
  #add-link-btn:hover, #update-link-btn:hover {
    background-color: #0056b3;
  }
  
  .modal-footer {
    padding: 15px 20px;
    border-top: 1px solid #dee2e6;
    background-color: #f8f9fa;
    text-align: center;
  }
  
  .modal-footer button {
    padding: 10px 20px;
    background-color: #6c757d;
    color: white;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
  }
  
  .modal-footer button:hover {
    background-color: #545b62;
  }
  
  .modal-content input {
    display: block;
    width: 90%;
    margin: 10px auto;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    flex-shrink: 0;
  }
  
  .modal-content button {
    margin: 5px;
    padding: 10px 15px;
    border: none;
    border-radius: 5px;
    background-color: #666;
    color: white;
    cursor: pointer;
    flex-shrink: 0;
  }
  
  .modal-content button:hover {
    background-color: #444;
  }
  
  .link-list {
    margin-bottom: 15px;
  }
  
  .edit-button {
    display: none;
    position: absolute;
    top: 10px;
    right: 10px;
    background-color: #999;
    color: white;
    font-size: 12px;
    padding: 8px 12px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
  }
  
  .section:hover .edit-button {
    display: block;
  }
  
  .edit-button:hover {
    background-color: #666;
  }
  
  .edit-button:active {
    background-color: #444;
  }
  
  .data-management {
    position: fixed;
    bottom: 20px;
    right: 40px;
    display: flex;
    gap: 10px;
  }
  
  .data-management button {
    margin: 0;
    padding: 10px 15px;
    font-size: 10px;
    background-color: #666;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
  }
  
  .data-management button:hover {
    background-color: #444;
  }
  
  .navigation-link.google-link {
    background-color: #e0e0e0;
    color: black;
    font-weight: bold;
    font-size: 12px;
    text-decoration: none;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background-color 0.3s, transform 0.2s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  
  .navigation-link.google-link:hover {
    background-color: #d0d0d0;
    transform: scale(1.05);
  }

  .navigation-link.claude-link {
    background-color: #e0e0e0;
    color: black;
    font-weight: bold;
    font-size: 12px;
    text-decoration: none;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background-color 0.3s, transform 0.2s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  
  .navigation-link.claude-link:hover {
    background-color: #d0d0d0;
    transform: scale(1.05);
  }
  
  #modal-link-list {
    list-style: none;
    padding: 0;
    margin: 0;
    flex-grow: 1;
    overflow-y: auto;
    max-height: 300px;
  }
  
  #modal-link-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    border-bottom: 1px solid #ddd;
    cursor: move;
    transition: background-color 0.2s, opacity 0.2s;
    border-radius: 6px;
    margin-bottom: 8px;
    background-color: #fff;
    border: 1px solid #e0e0e0;
  }
  
  .link-item-actions {
    display: flex;
    gap: 5px;
  }
  
  .link-item-actions button {
    padding: 4px 8px;
    font-size: 12px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s;
  }
  
  .link-item-actions button:first-child {
    background-color: #007bff;
    color: white;
  }
  
  .link-item-actions button:first-child:hover {
    background-color: #0056b3;
  }
  
  .link-item-actions button:last-child {
    background-color: #dc3545;
    color: white;
  }
  
  .link-item-actions button:last-child:hover {
    background-color: #c82333;
  }
  
  .inline-badge {
    background-color: #28a745;
    color: white;
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 3px;
    margin-left: 8px;
  }
  
  .editing-badge {
    background-color: #007bff;
    color: white;
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 3px;
    margin-left: 8px;
    animation: pulse 1.5s infinite;
  }
  
  @keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.6; }
    100% { opacity: 1; }
  }
  
  .editing-item {
    background-color: #e3f2fd !important;
    border: 2px solid #007bff !important;
    box-shadow: 0 2px 8px rgba(0, 123, 255, 0.3);
  }

  #modal-link-list li:hover {
    background-color: #f0f0f0;
  }

  #modal-link-list li.dragging {
    opacity: 0.5;
    background-color: #e8f4f8;
  }

  #modal-link-list li.drag-over {
    background-color: #d4edda;
    border: 2px dashed #28a745;
  }

  .drag-handle {
    color: #999;
    font-size: 16px;
    cursor: grab;
    margin-right: 10px;
    user-select: none;
  }

  /* ヘッダーリンク編集フォーム */
  .header-link-edit-form {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    border: 2px solid #007bff;
  }

  .edit-form-row {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
  }

  .edit-text-input,
  .edit-url-input {
    flex: 1;
    padding: 8px 12px;
    border: 2px solid #e9ecef;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.2s ease;
  }

  .edit-text-input:focus,
  .edit-url-input:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
  }

  .edit-form-actions {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
  }

  .save-btn,
  .cancel-btn {
    padding: 6px 12px;
    border: none;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
  }

  .save-btn {
    background: #28a745;
    color: white;
  }

  .save-btn:hover {
    background: #218838;
  }

  .cancel-btn {
    background: #6c757d;
    color: white;
  }

  .cancel-btn:hover {
    background: #545b62;
  }

  /* ヘッダーリンク ドラッグ&ドロップスタイル */
  #modal-header-link-list li.dragging {
    opacity: 0.5;
    background-color: #e8f4f8;
    transform: scale(1.02);
  }

  #modal-header-link-list li.drag-over {
    background-color: #d4edda;
    border: 2px dashed #28a745;
  }

  .drag-handle:active {
    cursor: grabbing;
  }

  .link-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    gap: 5px;
  }

  .link-text {
    font-weight: bold;
    color: #333;
  }

  .link-url {
    color: #007bff;
    text-decoration: none;
    font-size: 12px;
    word-break: break-all;
  }
  
  
  #modal-link-list li button {
    padding: 5px 10px;
    font-size: 14px;
    background-color: #ff4d4d;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
  }
  
  #modal-link-list li button:hover {
    background-color: #cc0000;
  }
  
  .modal-content textarea {
    width: 100%;
    height: 100px; /* 固定サイズ */
    margin-top: 10px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    resize: none; /* リサイズ不可 */
    font-size: 14px;
    color: #333;
    background-color: #f9f9f9;
  }

  /* メインタイトルとナビゲーションリンクの編集スタイル */
  .title-input {
    display: none;
    font-family: 'Comic Sans MS', 'Arial', sans-serif;
    font-size: 36px;
    font-weight: bold;
    text-align: center;
    background: transparent;
    border: 2px dashed #666;
    border-radius: 5px;
    padding: 5px;
    color: #333;
    letter-spacing: 1.5px;
  }

  .title-input:focus {
    outline: none;
    border-color: #007bff;
  }

  #main-title {
    cursor: pointer;
  }

  #main-title:hover {
    opacity: 0.8;
  }

  /* SPA機能のスタイル */
  .view {
    display: none;
  }

  .view.active {
    display: block;
  }

  .nav-tab.active {
    background-color: #007bff;
    color: white;
    border: 2px solid #0056b3;
    font-weight: bold;
    transform: scale(1.05);
    box-shadow: 0 2px 4px rgba(0,123,255,0.3);
  }

  .add-project-footer-btn {
    background-color: #4CAF50;
    color: white;
    border: none;
    cursor: pointer;
    font-size: 10px;
    font-weight: bold;
    padding: 10px 15px;
    border-radius: 5px;
    transition: background-color 0.3s;
  }

  .add-project-footer-btn:hover {
    background-color: #45a049;
  }

  .delete-project-footer-btn {
    background-color: #f44336;
    color: white;
    border: none;
    cursor: pointer;
    font-size: 10px;
    font-weight: bold;
    padding: 10px 15px;
    border-radius: 5px;
    transition: background-color 0.3s;
  }

  .delete-project-footer-btn:hover {
    background-color: #da190b;
  }

  /* レスポンシブ対応 - 基本設定 */
  body {
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
  }

  .App {
    max-width: 100%;
    padding: 10px;
  }

  /* レスポンシブ対応 - ナビゲーション */
  .header-navigation {
    position: relative;
  }

  .mobile-menu-toggle {
    display: none;
    background: #666;
    color: white;
    border: none;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    margin-bottom: 10px;
  }

  @media (max-width: 768px) {
    .App {
      padding: 5px;
    }

    .main-header {
      gap: 6px;
      margin-bottom: 8px;
    }
    
    .title-header {
      min-height: 35px;
      padding: 3px 0;
      margin-bottom: 6px;
      flex-direction: column;
      align-items: stretch;
      gap: 8px;
    }

    .title-left {
      text-align: center;
    }
    
    .title-left h1 {
      font-size: 18px;
      letter-spacing: 0.8px;
    }

    .title-right {
      justify-content: center;
    }

    #header-links-container {
      max-width: 100%;
      flex-wrap: wrap;
      justify-content: center;
    }

    .header-link {
      font-size: 12px;
      padding: 6px 10px;
      min-width: 50px;
    }

    /* ナビゲーションメニューの改善 */
    .mobile-menu-toggle {
      display: block;
    }

    .fixed-buttons-group,
    .dynamic-buttons-group {
      display: none;
      flex-direction: column;
      gap: 8px;
      background: #f8f9fa;
      border: 1px solid #ddd;
      border-radius: 8px;
      padding: 10px;
      margin-top: 5px;
    }

    .fixed-buttons-group.show,
    .dynamic-buttons-group.show {
      display: flex;
    }
    
    .navigation-link {
      font-size: 12px;
      padding: 8px 12px;
      text-align: center;
      width: 100%;
      box-sizing: border-box;
    }
    
    .enhanced-section {
      margin-bottom: 15px;
    }
    
    .section-header {
      padding: 10px 12px;
    }
    
    .section-title-text {
      font-size: 14px;
    }
    
    .link-grid {
      grid-template-columns: repeat(2, 1fr);
      padding: 10px;
      gap: 4px;
    }
    
    .link-card-content {
      padding: 5px 8px;
      min-height: 24px;
    }
    
    .link-favicon {
      font-size: 12px;
      margin-right: 6px;
    }
    
    .link-title {
      font-size: 12px;
    }
    
    .action-btn {
      padding: 4px;
      font-size: 12px;
    }

    /* セクショングリッドの改善 */
    .section-grid {
      grid-template-columns: 1fr;
      gap: 15px;
    }

    /* モーダルの改善 */
    .modal-content {
      width: 95%;
      max-height: 85vh;
      margin: 5% auto;
    }

    .modal-body {
      padding: 15px;
    }

    /* フッターボタンの改善 */
    .data-management {
      position: relative;
      bottom: auto;
      right: auto;
      margin-top: 20px;
      justify-content: center;
      flex-wrap: wrap;
      gap: 5px;
    }

    .data-management button {
      font-size: 12px;
      padding: 8px 12px;
    }
  }

  @media (max-width: 480px) {
    .App {
      padding: 2px;
    }

    .title-left h1 {
      font-size: 16px;
    }

    .header-link {
      font-size: 10px;
      padding: 4px 8px;
      min-width: 40px;
    }

    .navigation-link {
      font-size: 10px;
      padding: 6px 10px;
    }

    .link-grid {
      grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
      padding: 8px;
      gap: 3px;
    }
    
    .section-header {
      padding: 8px 10px;
    }
    
    .section-title-text {
      font-size: 13px;
    }
    
    .section-subtitle {
      font-size: 10px;
    }
    
    .link-card-content {
      padding: 4px 6px;
      min-height: 20px;
    }
    
    .link-favicon {
      font-size: 11px;
      margin-right: 5px;
    }
    
    .link-title {
      font-size: 11px;
    }

    .modal-content {
      width: 98%;
      margin: 2% auto;
    }

    .data-management button {
      font-size: 10px;
      padding: 6px 10px;
    }
  }

  /* タッチデバイス対応 */
  @media (hover: none) and (pointer: coarse) {
    .action-btn {
      opacity: 1;
    }

    .link-actions {
      opacity: 1;
    }

    .edit-button {
      display: block;
    }
  }

  #project-links {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
  }

  /* ウェルカムメッセージのスタイル */
  .welcome-message {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 400px;
    padding: 40px;
  }

  .welcome-content {
    max-width: 600px;
    text-align: center;
    background-color: #f8f9fa;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  }

  .welcome-content h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 28px;
  }

  .welcome-content p {
    color: #666;
    margin-bottom: 30px;
    font-size: 16px;
    line-height: 1.6;
  }

  .welcome-features {
    text-align: left;
    margin-top: 30px;
  }

  .welcome-features h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 20px;
    text-align: center;
  }

  .welcome-features ul {
    list-style: none;
    padding: 0;
  }

  .welcome-features li {
    padding: 8px 0;
    color: #555;
    font-size: 14px;
  }

  /* ウェルカムメッセージのアクションボタン */
  .welcome-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin: 30px 0;
    flex-wrap: wrap;
  }

  .start-mypage-btn, .add-project-btn {
    padding: 12px 24px;
    font-size: 16px;
    font-weight: bold;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
  }

  .start-mypage-btn {
    background: linear-gradient(135deg, #4CAF50, #45a049);
    color: white;
    box-shadow: 0 4px 8px rgba(76, 175, 80, 0.3);
  }

  .start-mypage-btn:hover {
    background: linear-gradient(135deg, #45a049, #4CAF50);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(76, 175, 80, 0.4);
  }

  .add-project-btn {
    background: linear-gradient(135deg, #2196F3, #1976D2);
    color: white;
    box-shadow: 0 4px 8px rgba(33, 150, 243, 0.3);
  }

  .add-project-btn:hover {
    background: linear-gradient(135deg, #1976D2, #2196F3);
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(33, 150, 243, 0.4);
  }

  /* プロジェクト削除モーダルのスタイル */
  .delete-form {
    margin: 20px 0;
  }

  .delete-form label {
    display: block;
    margin-bottom: 10px;
    font-weight: bold;
    color: #333;
  }

  .project-select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
    background-color: white;
    color: #333;
  }

  .project-select:focus {
    outline: none;
    border-color: #007cba;
    box-shadow: 0 0 5px rgba(0, 124, 186, 0.3);
  }

  .modal-buttons {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 20px;
  }

  .modal-buttons button {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s;
  }

  .modal-buttons button:first-child {
    background-color: #dc3545;
    color: white;
  }

  .modal-buttons button:first-child:hover:not(:disabled) {
    background-color: #c82333;
  }

  .modal-buttons button:first-child:disabled {
    background-color: #6c757d;
    cursor: not-allowed;
  }

  .modal-buttons button:last-child {
    background-color: #6c757d;
    color: white;
  }

  .modal-buttons button:last-child:hover {
    background-color: #545b62;
  }