/* ============================================
   IT情報保管庫 専用スタイルシート
   repository.css
   ============================================ */

/* ============================================
   1. カテゴリーグリッド
   ============================================ */

/* カテゴリーグリッドコンテナ */
.category-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin: 2rem 0;
}

/* カテゴリーカード */
.category-card {
    position: relative;
    padding: 2rem;
    border-radius: 24px;
    overflow: hidden;
    transition: all var(--transition-base);
    cursor: pointer;
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-md);
    text-decoration: none;
    display: block;
}

.category-card:hover {
    box-shadow: var(--shadow-lg);
}

/* カテゴリーカード - アイコン */
.category-card-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.15));
}

/* カテゴリーカード - タイトル */
.category-card-title {
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: 0.5rem;
    color: white;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* カテゴリーカード - 説明 */
.category-card-desc {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 1rem;
    line-height: 1.6;
}

/* カテゴリーカード - 統計情報 */
.category-card-stats {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.8);
}

.category-card-stat {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* ============================================
   2. カテゴリー別グラデーション
   ============================================ */

.category-git {
    background: linear-gradient(135deg, #FF9F0A, #FF3B30);
}

.category-docker {
    background: linear-gradient(135deg, #0A84FF, #007AFF);
}

.category-linux {
    background: linear-gradient(135deg, #FF9F0A, #FF8C00);
}

.category-windows {
    background: linear-gradient(135deg, #0A84FF, #00BCF2);
}

.category-vscode {
    background: linear-gradient(135deg, #007ACC, #005A9E);
}

.category-vim {
    background: linear-gradient(135deg, #019733, #00701A);
}

.category-text-processing {
    background: linear-gradient(135deg, #BF5AF2, #AF52DE);
}

.category-network {
    background: linear-gradient(135deg, #30D158, #28CD4C);
}

.category-permissions {
    background: linear-gradient(135deg, #FF9F0A, #FF8C00);
}

.category-kubernetes {
    background: linear-gradient(135deg, #326CE5, #2B5FD9);
}

.category-tmux {
    background: linear-gradient(135deg, #1BB91F, #159619);
}

.category-systemctl {
    background: linear-gradient(135deg, #FF453A, #D93026);
}

.category-package-manager {
    background: linear-gradient(135deg, #BF5AF2, #9F4AD9);
}

.category-cloud {
    background: linear-gradient(135deg, #FF9F0A, #FFA724);
}

.category-database {
    background: linear-gradient(135deg, #0A84FF, #0070F3);
}

.category-scheduling {
    background: linear-gradient(135deg, #30D158, #2AB04C);
}

.category-sql {
    background: linear-gradient(135deg, #007AFF, #005ECC);
}

.category-archive {
    background: linear-gradient(135deg, #8E8E93, #636366);
}

/* ============================================
   3. クイックアクセスセクション
   ============================================ */

.quick-access-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    margin: 2rem 0;
}

.quick-access-card {
    background: var(--macos-card);
    backdrop-filter: var(--glass-blur) var(--glass-saturate);
    -webkit-backdrop-filter: var(--glass-blur) var(--glass-saturate);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 20px;
    padding: 1.5rem;
    text-align: center;
    transition: all var(--transition-base);
    cursor: pointer;
    text-decoration: none;
    display: block;
    box-shadow: var(--shadow-sm);
}

.quick-access-card:hover {
    box-shadow: var(--shadow-md);
}

.quick-access-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: inline-block;
}

.quick-access-title {
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-gray-800);
    margin-bottom: 0.5rem;
}

.quick-access-count {
    font-size: 0.875rem;
    color: var(--color-gray-600);
}

/* ============================================
   4. 検索バー
   ============================================ */

.repository-search-container {
    position: relative;
    max-width: 600px;
    margin: 2rem auto;
}

.repository-search {
    width: 100%;
    padding: 1rem 1.5rem 1rem 3.5rem;
    border-radius: 50px;
    border: 2px solid transparent;
    background: white;
    font-size: 1rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
}

.repository-search:focus {
    outline: none;
    border-color: var(--macos-blue);
    box-shadow: 0 0 0 4px rgba(10, 132, 255, 0.1), var(--shadow-lg);
}

.repository-search-icon {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-gray-400);
    font-size: 1.25rem;
    pointer-events: none;
}

/* ============================================
   5. 統計情報バッジ
   ============================================ */

.stats-container {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.stats-badge {
    background: linear-gradient(135deg, rgba(10, 132, 255, 0.1), rgba(0, 122, 255, 0.05));
    border: 1px solid rgba(10, 132, 255, 0.2);
    border-radius: 16px;
    padding: 1rem 1.5rem;
    text-align: center;
    min-width: 150px;
    transition: all var(--transition-base);
}


.stats-number {
    font-size: 2rem;
    font-weight: var(--font-weight-black);
    background: linear-gradient(135deg, var(--macos-blue), #005ECC);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
    line-height: 1.2;
}

.stats-label {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    margin-top: 0.25rem;
    font-weight: var(--font-weight-medium);
}

/* ============================================
   6. 人気コマンドリスト
   ============================================ */

.popular-commands-list {
    max-width: 800px;
    margin: 2rem auto;
}

.popular-command-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    background: white;
    border-radius: 16px;
    margin-bottom: 1rem;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid rgba(0, 0, 0, 0.04);
}

.popular-command-item:hover {
    box-shadow: var(--shadow-md);
}

.popular-command-rank {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-bold);
    font-size: 0.875rem;
    margin-right: 1rem;
    flex-shrink: 0;
}

.popular-command-rank.rank-1 {
    background: linear-gradient(135deg, #FFD700, #FFA500);
    color: white;
    box-shadow: 0 4px 12px rgba(255, 215, 0, 0.4);
}

.popular-command-rank.rank-2 {
    background: linear-gradient(135deg, #C0C0C0, #A8A8A8);
    color: white;
    box-shadow: 0 4px 12px rgba(192, 192, 192, 0.4);
}

.popular-command-rank.rank-3 {
    background: linear-gradient(135deg, #CD7F32, #B87333);
    color: white;
    box-shadow: 0 4px 12px rgba(205, 127, 50, 0.4);
}

.popular-command-rank.rank-other {
    background: var(--color-gray-200);
    color: var(--color-gray-700);
}

.popular-command-content {
    flex: 1;
    min-width: 0;
}

.popular-command-code {
    font-family: 'JetBrains Mono', 'SF Mono', 'Consolas', monospace;
    font-size: 0.95rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-gray-800);
    margin-bottom: 0.25rem;
}

.popular-command-desc {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    line-height: 1.4;
}

.popular-command-copy {
    padding: 0.5rem 1rem;
    border-radius: 8px;
    background: var(--macos-blue);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: var(--font-weight-semibold);
    transition: all var(--transition-fast);
    flex-shrink: 0;
    margin-left: 1rem;
}

.popular-command-copy:hover {
    background: #007AFF;
}

.popular-command-copy:active {
    background: #0056b3;
}

/* ============================================
   7. サイドバー
   ============================================ */

.repository-sidebar {
    width: 260px;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    background: white;
    border-right: 1px solid var(--macos-border);
    overflow-y: auto;
    padding: 1.5rem 0;
    padding-top: 5rem;
    z-index: 40;
    transition: transform 0.3s ease;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.05);
}

/* サイドバーオーバーレイ */
.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    opacity: 0;
    visibility: hidden;
    z-index: 35;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* サイドバートグルボタン */
.sidebar-toggle-btn {
    position: fixed;
    left: 1rem;
    bottom: 1.5rem;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, #1b87f5, #146fe1);
    color: white;
    border: none;
    box-shadow: 0 4px 16px rgba(20, 111, 225, 0.4);
    cursor: pointer;
    z-index: 50;
    transition: all 0.3s ease;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.sidebar-toggle-btn:hover {
    box-shadow: 0 6px 20px rgba(20, 111, 225, 0.5);
}

.sidebar-toggle-btn:active {
    opacity: 0.9;
}

.sidebar-toggle-btn.active {
    background: linear-gradient(135deg, #ef4444, #dc2626);
}

.repository-sidebar-header {
    padding: 0 1.5rem 1rem;
    border-bottom: 1px solid var(--macos-border);
    margin-bottom: 1rem;
}

.repository-sidebar-title {
    font-size: 0.75rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-gray-600);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* サイドバーナビゲーション */
.sidebar-nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-nav-group {
    margin-bottom: 1.5rem;
}

.sidebar-nav-group-title {
    padding: 0.5rem 1.5rem;
    font-size: 0.875rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-gray-700);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all var(--transition-fast);
}

.sidebar-nav-group-title:hover {
    background: var(--color-gray-50);
    color: var(--macos-blue);
}

.sidebar-nav-group-icon {
    transition: transform var(--transition-fast);
}

.sidebar-nav-group.collapsed .sidebar-nav-group-icon {
    transform: rotate(-90deg);
}

.sidebar-nav-items {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 1000px;
    overflow: hidden;
    transition: max-height var(--transition-base);
}

.sidebar-nav-group.collapsed .sidebar-nav-items {
    max-height: 0;
}

.sidebar-nav-item {
    margin: 0;
}

.sidebar-nav-link {
    display: flex;
    align-items: center;
    padding: 0.75rem 1.5rem 0.75rem 2.5rem;
    color: var(--color-gray-700);
    text-decoration: none;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
    position: relative;
}

.sidebar-nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: var(--macos-blue);
    transition: height var(--transition-fast);
}

.sidebar-nav-link:hover {
    background: var(--color-gray-50);
    color: var(--macos-blue);
}

.sidebar-nav-link.active {
    background: linear-gradient(90deg, rgba(10, 132, 255, 0.1), transparent);
    color: var(--macos-blue);
    font-weight: var(--font-weight-semibold);
}

.sidebar-nav-link.active::before {
    height: 100%;
}

/* サイドバートグルボタン（モバイル用） */
.sidebar-toggle {
    display: none;
    position: fixed;
    bottom: 2rem;
    left: 1rem;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--macos-blue);
    color: white;
    border: none;
    box-shadow: 0 4px 16px rgba(10, 132, 255, 0.4);
    cursor: pointer;
    z-index: var(--z-fixed);
    transition: all var(--transition-base);
    font-size: 1.5rem;
}

.sidebar-toggle:hover {
    box-shadow: 0 6px 20px rgba(10, 132, 255, 0.5);
}

.sidebar-toggle:active {
    opacity: 0.9;
}

/* サイドバーオーバーレイ（モバイル用） */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: calc(var(--z-fixed) - 1);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.sidebar-overlay.visible {
    opacity: 1;
}

/* ============================================
   8. パンくずナビゲーション
   ============================================ */

.breadcrumb {
    display: flex;
    align-items: center;
    padding: 1rem 0;
    font-size: 0.875rem;
    color: var(--color-gray-600);
    flex-wrap: wrap;
}

.breadcrumb-item {
    display: flex;
    align-items: center;
}

.breadcrumb-link {
    color: var(--macos-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.breadcrumb-link:hover {
    color: #007AFF;
    text-decoration: underline;
}

.breadcrumb-separator {
    margin: 0 0.5rem;
    color: var(--color-gray-400);
}

.breadcrumb-current {
    color: var(--color-gray-800);
    font-weight: var(--font-weight-medium);
}

/* ============================================
   9. レスポンシブデザイン
   ============================================ */

/* デスクトップ：サイドバー常時表示 */
@media (min-width: 1025px) {
    .sidebar-toggle-btn {
        display: none !important;
    }

    .sidebar-overlay {
        display: none !important;
    }
}

/* タブレット（1024px以下） */
@media (max-width: 1024px) {
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }

    .quick-access-container {
        grid-template-columns: repeat(2, 1fr);
    }

    /* サイドバー: モバイル表示に切り替え */
    .repository-sidebar {
        width: 280px;
        transform: translateX(-100%);
    }

    .repository-sidebar.mobile-visible {
        transform: translateX(0);
    }

    .sidebar-toggle-btn {
        display: flex;
    }

    .repository-main-content {
        margin-left: 0 !important;
    }
}

/* モバイル（768px以下） */
@media (max-width: 768px) {
    .category-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .quick-access-container {
        grid-template-columns: 1fr;
    }

    .repository-sidebar {
        width: 85vw;
        max-width: 320px;
    }

    .stats-container {
        gap: 1rem;
    }

    .stats-badge {
        min-width: 120px;
        padding: 0.75rem 1rem;
    }

    .stats-number {
        font-size: 1.5rem;
    }

    .popular-command-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .popular-command-copy {
        margin-left: 0;
        width: 100%;
    }

    .category-card {
        padding: 1.5rem;
    }

    .category-card-icon {
        font-size: 2.5rem;
    }

    .category-card-title {
        font-size: 1.25rem;
    }

    .repository-search {
        font-size: 0.875rem;
        padding: 0.875rem 1.25rem 0.875rem 3rem;
    }

    .breadcrumb {
        font-size: 0.75rem;
    }
}

/* 小型モバイル（480px以下） */
@media (max-width: 480px) {
    .category-card {
        padding: 1.25rem;
    }

    .quick-access-card {
        padding: 1.25rem;
    }

    .popular-command-rank {
        width: 28px;
        height: 28px;
        font-size: 0.75rem;
    }

    .repository-search-container {
        margin: 1.5rem 0;
    }
}

/* ============================================
   10. ダークモード対応
   ============================================ */

body.dark-mode .category-card {
    border-color: rgba(255, 255, 255, 0.15);
}

body.dark-mode .quick-access-card {
    background: rgba(30, 30, 30, 0.7);
    border-color: rgba(255, 255, 255, 0.15);
}

body.dark-mode .quick-access-title {
    color: var(--color-gray-200);
}

body.dark-mode .quick-access-count {
    color: var(--color-gray-400);
}

body.dark-mode .repository-search {
    background: rgba(30, 30, 30, 0.9);
    color: white;
    border-color: rgba(255, 255, 255, 0.15);
}

body.dark-mode .repository-search::placeholder {
    color: var(--color-gray-500);
}

body.dark-mode .stats-badge {
    background: linear-gradient(135deg, rgba(10, 132, 255, 0.2), rgba(0, 122, 255, 0.1));
    border-color: rgba(10, 132, 255, 0.3);
}

body.dark-mode .popular-command-item {
    background: rgba(30, 30, 30, 0.7);
    border-color: rgba(255, 255, 255, 0.1);
}

body.dark-mode .popular-command-code {
    color: var(--color-gray-200);
}

body.dark-mode .popular-command-desc {
    color: var(--color-gray-400);
}

body.dark-mode .repository-sidebar {
    background: rgba(20, 20, 20, 0.95);
    border-right-color: rgba(255, 255, 255, 0.1);
}

body.dark-mode .sidebar-nav-group-title {
    color: var(--color-gray-300);
}

body.dark-mode .sidebar-nav-group-title:hover {
    background: rgba(255, 255, 255, 0.05);
}

body.dark-mode .sidebar-nav-link {
    color: var(--color-gray-300);
}

body.dark-mode .sidebar-nav-link:hover {
    background: rgba(255, 255, 255, 0.05);
}

body.dark-mode .sidebar-nav-link.active {
    background: linear-gradient(90deg, rgba(10, 132, 255, 0.2), transparent);
}

body.dark-mode .breadcrumb-link {
    color: var(--macos-blue);
}

body.dark-mode .breadcrumb-current {
    color: var(--color-gray-200);
}

/* ============================================
   11. アニメーション
   ============================================ */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-fade-in-up {
    animation: fadeInUp 0.6s ease-out forwards;
}

.animate-fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}

.animate-slide-in-left {
    animation: slideInLeft 0.5s ease-out forwards;
}

/* アニメーション遅延 */
.animation-delay-100 {
    animation-delay: 0.1s;
}

.animation-delay-200 {
    animation-delay: 0.2s;
}

.animation-delay-300 {
    animation-delay: 0.3s;
}

.animation-delay-400 {
    animation-delay: 0.4s;
}

.animation-delay-500 {
    animation-delay: 0.5s;
}

/* ============================================
   12. ユーティリティクラス
   ============================================ */

.repository-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

.repository-section {
    margin-bottom: 4rem;
}

.repository-section-title {
    font-size: 2rem;
    font-weight: var(--font-weight-black);
    color: var(--color-gray-900);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

body.dark-mode .repository-section-title {
    color: var(--color-gray-100);
}

.repository-section-subtitle {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    margin-bottom: 2rem;
    line-height: 1.6;
}

body.dark-mode .repository-section-subtitle {
    color: var(--color-gray-400);
}

/* コンテンツエリア（サイドバー使用時） */
.repository-main-content {
    margin-left: 280px;
    transition: margin-left var(--transition-base);
}

@media (max-width: 1024px) {
    .repository-main-content {
        margin-left: 240px;
    }
}

@media (max-width: 768px) {
    .repository-main-content {
        margin-left: 0;
    }

    .repository-container {
        padding: 1rem;
    }

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

    .repository-section-title {
        font-size: 1.5rem;
    }

    .repository-section-subtitle {
        font-size: 1rem;
    }
}

/* 検索ハイライト */
.search-highlight {
    background-color: rgba(27, 135, 245, 0.1) !important;
    border-left: 3px solid #1b87f5 !important;
}

/* サイドバーナビゲーションアイテム（all.html用） */
.sidebar-nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    color: #4b5563;
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    border-radius: 8px;
    margin: 0.25rem 0.75rem;
}

.sidebar-nav-item:hover {
    background: #f3f4f6;
    color: #1b87f5;
}

.sidebar-nav-item.active {
    background: linear-gradient(135deg, rgba(27, 135, 245, 0.1), rgba(20, 111, 225, 0.05));
    color: #1b87f5;
    font-weight: 600;
}

.sidebar-nav-item i {
    width: 20px;
    text-align: center;
    font-size: 1rem;
}

/* サイドバーヘッダー */
.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid #e5e7eb;
    margin-bottom: 0.5rem;
}

.sidebar-header h2 {
    font-size: 1rem;
    font-weight: 700;
    color: #1f2937;
    margin: 0;
}

#sidebar-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    color: #6b7280;
    transition: color 0.2s;
}

#sidebar-close:hover {
    color: #1f2937;
}

/* アクセシビリティ: スクリーンリーダー専用 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* フォーカス表示 */
.category-card:focus,
.quick-access-card:focus,
.sidebar-nav-link:focus,
.popular-command-copy:focus {
    outline: 2px solid var(--macos-blue);
    outline-offset: 2px;
}

/* ============================================
   13. プリント用スタイル
   ============================================ */

@media print {
    .repository-sidebar,
    .sidebar-toggle,
    .sidebar-overlay,
    .quick-access-container,
    .repository-search-container {
        display: none !important;
    }

    .repository-main-content {
        margin-left: 0;
    }

    .category-card {
        break-inside: avoid;
    }

    .popular-command-item {
        break-inside: avoid;
    }
}

/* ============================================
   14. メインカテゴリカード（4カラムトップ用）
   ============================================ */

/* 2x2グリッドレイアウト */
.main-category-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    max-width: 1000px;
    margin: 3rem auto;
    padding: 0 2rem;
}

/* 大きなカテゴリカード */
.main-category-card {
    position: relative;
    padding: 3rem;
    border-radius: 24px;
    overflow: hidden;
    transition: all 0.3s ease;
    cursor: pointer;
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    text-decoration: none;
    display: flex;
    flex-direction: column;
    min-height: 280px;
}

.main-category-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.2);
}

.main-category-card .category-card-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    display: block;
}

.main-category-card .category-card-title {
    font-size: 2rem;
    font-weight: 900;
    color: white;
    margin-bottom: 0.75rem;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.main-category-card .category-card-desc {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

/* カテゴリ別グラデーション（4カテゴリ）- グレー系ニュートラル */
.category-theory {
    background: linear-gradient(135deg, #6b7280, #4b5563);
}

.category-news {
    background: linear-gradient(135deg, #78716c, #57534e);
}

.category-practice {
    background: linear-gradient(135deg, #64748b, #475569);
}

.category-cheatsheet {
    background: linear-gradient(135deg, #71717a, #52525b);
}

/* レスポンシブ */
@media (max-width: 768px) {
    .main-category-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 0 1rem;
        margin: 2rem auto;
    }

    .main-category-card {
        padding: 2rem;
        min-height: 200px;
    }

    .main-category-card .category-card-icon {
        font-size: 3rem;
        margin-bottom: 1rem;
    }

    .main-category-card .category-card-title {
        font-size: 1.5rem;
    }

    .main-category-card .category-card-desc {
        font-size: 0.9rem;
    }
}

/* ============================================
   15. 記事カードスタイル
   ============================================ */

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

.article-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
}

.article-thumbnail {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, #f5f7fa, #c3cfe2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
}

.article-content {
    padding: 1.5rem;
}

.article-category {
    display: inline-block;
    background: rgba(107, 114, 128, 0.1);
    color: #6b7280;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.article-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.article-card p {
    font-size: 0.875rem;
    color: #6b7280;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.article-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.75rem;
    color: #9ca3af;
}

/* ============================================
   16. チュートリアルカードスタイル
   ============================================ */

.tutorial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.tutorial-card {
    background: white;
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border-left: 4px solid #64748b;
    text-decoration: none;
    color: inherit;
    display: block;
}

.tutorial-card:hover {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.tutorial-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.tutorial-level {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
}

.level-beginner { background: #d1fae5; color: #065f46; }
.level-intermediate { background: #fef3c7; color: #92400e; }
.level-advanced { background: #fee2e2; color: #991b1b; }

.tutorial-time {
    font-size: 0.75rem;
    color: #9ca3af;
}

.tutorial-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.tutorial-card p {
    font-size: 0.875rem;
    color: #6b7280;
    line-height: 1.5;
    margin-bottom: 1rem;
}

.tutorial-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tutorial-tags span {
    background: #f3f4f6;
    color: #4b5563;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
}

/* ============================================
   17. 記事カードスタイル（Zenn風シンプルデザイン）
   ============================================ */

.news-grid {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.news-card {
    padding: 1.25rem 0;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
    border-bottom: 1px solid #e5e7eb;
    transition: opacity 0.15s ease;
}

.news-card:first-child {
    padding-top: 0;
}

.news-card:last-child {
    border-bottom: none;
}

.news-card:hover {
    opacity: 0.7;
}

.news-card h3 {
    font-size: 1rem;
    font-weight: 700;
    color: #1a1a1a;
    line-height: 1.6;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-card p {
    font-size: 0.875rem;
    color: #6b7280;
    line-height: 1.7;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-meta {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.8rem;
    margin-top: 0.25rem;
}

.news-date {
    color: #9ca3af;
}

.news-tag {
    color: #3b82f6;
    font-size: 0.8rem;
    font-weight: 500;
}

/* ============================================
   18. フィルタータブ（Zenn風シンプル）
   ============================================ */

.filter-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.filter-tabs button {
    padding: 0.4rem 0.8rem;
    border: 1px solid #e5e7eb;
    border-radius: 100px;
    background: white;
    color: #6b7280;
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s ease;
}

.filter-tabs button:hover {
    border-color: #3b82f6;
    color: #3b82f6;
}

.filter-tabs button.active {
    background: #3b82f6;
    border-color: #3b82f6;
    color: white;
}

/* ============================================
   19. セクションヘッダー（Zenn風シンプル）
   ============================================ */

.section-header {
    text-align: left;
    margin-bottom: 1.5rem;
}

.section-header h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1a1a1a;
    margin-bottom: 0.25rem;
}

.section-header p {
    font-size: 0.875rem;
    color: #6b7280;
}

@media (max-width: 768px) {
    .section-header h1 {
        font-size: 1.125rem;
    }

    .section-header p {
        font-size: 0.8rem;
    }
}

/* ============================================
   20. ソートUI（Zenn風シンプル）
   ============================================ */

.sort-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.sort-label {
    font-size: 0.8rem;
    color: #9ca3af;
}

.sort-buttons {
    display: flex;
    gap: 0.25rem;
}

.sort-btn {
    padding: 0.35rem 0.6rem;
    border: none;
    border-radius: 4px;
    background: transparent;
    color: #9ca3af;
    font-size: 0.75rem;
    cursor: pointer;
    transition: color 0.15s ease;
}

.sort-btn:hover {
    color: #374151;
}

.sort-btn.active {
    color: #1a1a1a;
    font-weight: 600;
}

.sort-btn .icon {
    display: none;
}

/* ============================================
   21. 記事ページサイドバー
   ============================================ */

.article-page-layout {
    display: flex;
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem 4rem;
}

.article-main {
    flex: 1;
    min-width: 0;
}

.article-sidebar {
    width: 280px;
    flex-shrink: 0;
}

.sidebar-widget {
    background: white;
    border-radius: 12px;
    padding: 1.25rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    margin-bottom: 1.5rem;
}

.sidebar-widget-title {
    font-size: 0.9rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e5e7eb;
}

/* カテゴリナビ */
.sidebar-category-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-category-item {
    margin-bottom: 0.5rem;
}

.sidebar-category-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 0.75rem;
    border-radius: 8px;
    text-decoration: none;
    color: #4b5563;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.sidebar-category-link:hover {
    background: #f3f4f6;
    color: #6b7280;
}

.sidebar-category-link.active {
    background: rgba(107, 114, 128, 0.1);
    color: #6b7280;
    font-weight: 600;
}

.sidebar-category-icon {
    font-size: 1.1rem;
}

.sidebar-category-count {
    margin-left: auto;
    font-size: 0.75rem;
    color: #9ca3af;
    background: #f3f4f6;
    padding: 0.15rem 0.5rem;
    border-radius: 10px;
}

/* 最新記事 */
.sidebar-article-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-article-item {
    margin-bottom: 0.75rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid #f3f4f6;
}

.sidebar-article-item:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.sidebar-article-link {
    text-decoration: none;
    color: #4b5563;
    font-size: 0.85rem;
    line-height: 1.4;
    display: block;
    transition: color 0.2s;
}

.sidebar-article-link:hover {
    color: #6b7280;
}

.sidebar-article-date {
    font-size: 0.7rem;
    color: #9ca3af;
    margin-top: 0.25rem;
}

/* タグクラウド */
.tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag-cloud-item {
    display: inline-block;
    padding: 0.3rem 0.65rem;
    background: #f3f4f6;
    color: #4b5563;
    border-radius: 4px;
    font-size: 0.75rem;
    text-decoration: none;
    transition: all 0.2s;
}

.tag-cloud-item:hover {
    background: #6b7280;
    color: white;
}

.tag-cloud-item.large {
    font-size: 0.85rem;
    font-weight: 600;
}

/* 検索ボックス */
.sidebar-search {
    position: relative;
}

.sidebar-search-input {
    width: 100%;
    padding: 0.6rem 0.75rem 0.6rem 2.25rem;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.sidebar-search-input:focus {
    outline: none;
    border-color: #6b7280;
    box-shadow: 0 0 0 3px rgba(107, 114, 128, 0.1);
}

.sidebar-search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: #9ca3af;
    font-size: 0.85rem;
}

/* ============================================
   22. 関連記事セクション
   ============================================ */

.related-articles {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid #e5e7eb;
}

.related-articles-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1.5rem;
}

.related-articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.related-article-card {
    background: #f9fafb;
    border-radius: 12px;
    padding: 1.25rem;
    text-decoration: none;
    color: inherit;
    transition: all 0.2s;
}

.related-article-card:hover {
    background: #f3f4f6;
    transform: translateY(-2px);
}

.related-article-category {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    color: #6b7280;
    margin-bottom: 0.5rem;
}

.related-article-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: #1f2937;
    line-height: 1.4;
    margin-bottom: 0.5rem;
}

.related-article-date {
    font-size: 0.7rem;
    color: #9ca3af;
}

@media (max-width: 1024px) {
    .article-page-layout {
        flex-direction: column;
    }

    .article-sidebar {
        width: 100%;
        order: 2;
    }

    .article-main {
        order: 1;
    }
}

@media (max-width: 768px) {
    .article-page-layout {
        padding: 0 1rem 2rem;
    }

    .related-articles-grid {
        grid-template-columns: 1fr;
    }

    .sort-controls {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* ============================================
   23. level-elementary（beginner）追加
   ============================================ */

.level-elementary { background: #fef9c3; color: #854d0e; }

/* ============================================
   24. 記事なし表示
   ============================================ */

.no-articles {
    text-align: center;
    padding: 3rem;
    color: #9ca3af;
    font-size: 1rem;
}

/* ============================================
   25. タグフィルタ通知
   ============================================ */

.tag-filter-notice {
    background: #f3f4f6;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.tag-filter-notice span {
    color: #4b5563;
    font-size: 0.9rem;
}

.tag-filter-notice strong {
    color: #1f2937;
}

.clear-filter {
    color: #6b7280;
    text-decoration: none;
    font-size: 0.85rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    transition: all 0.2s;
}

.clear-filter:hover {
    background: #e5e7eb;
    color: #374151;
}

/* ============================================
   26. 記事ページ タグ表示
   ============================================ */

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.article-tag {
    background: #f3f4f6;
    color: #4b5563;
    padding: 0.3rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.85rem;
    text-decoration: none;
    transition: all 0.2s;
}

.article-tag:hover {
    background: #e5e7eb;
    color: #374151;
}