/* Google Fonts のインポート */
@import url('https://fonts.googleapis.com/css2?family=Fira+Code:wght@400;500&family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&display=swap');

:root {
  /* HSLを用いたモダンなカラーパレット */
  --bg-primary: hsl(220, 25%, 8%);
  --bg-secondary: hsl(220, 25%, 12%);
  --bg-tertiary: hsl(220, 25%, 16%);
  
  --glass-bg: hsla(220, 25%, 12%, 0.6);
  --glass-border: hsla(220, 25%, 25%, 0.3);
  --glass-highlight: hsla(0, 0%, 100%, 0.05);

  --text-primary: hsl(220, 20%, 95%);
  --text-secondary: hsl(220, 15%, 75%);
  --text-muted: hsl(220, 10%, 50%);

  --accent-primary: hsl(210, 100%, 60%);     /* Electric Blue */
  --accent-secondary: hsl(260, 90%, 65%);   /* Violet */
  --accent-gradient: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  --accent-glow: hsla(210, 100%, 60%, 0.15);

  --success: hsl(140, 70%, 45%);
  --warning: hsl(45, 90%, 50%);
  --danger: hsl(355, 80%, 55%);

  --font-sans: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'Fira Code', 'Courier New', monospace;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 20px var(--accent-glow);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
}

/* ライトモード対応 */
@media (prefers-color-scheme: light) {
  :root {
    --bg-primary: hsl(220, 20%, 97%);
    --bg-secondary: hsl(0, 0%, 100%);
    --bg-tertiary: hsl(220, 15%, 93%);
    
    --glass-bg: rgba(255, 255, 255, 0.75);
    --glass-border: rgba(220, 225, 235, 0.8);
    --glass-highlight: rgba(255, 255, 255, 0.4);

    --text-primary: hsl(220, 30%, 10%);
    --text-secondary: hsl(220, 15%, 35%);
    --text-muted: hsl(220, 10%, 60%);

    --accent-primary: hsl(210, 90%, 50%);
    --accent-secondary: hsl(260, 80%, 55%);
    --accent-glow: hsla(210, 90%, 50%, 0.1);
    
    --shadow-md: 0 8px 24px rgba(200, 205, 215, 0.25);
    --shadow-lg: 0 16px 48px rgba(200, 205, 215, 0.35);
  }
}

/* 基本リセット */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* スクロールバーのカスタマイズ */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

/* ヘッダー */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--glass-border);
  padding: 1.25rem 2rem;
}

.header-container {
  width: 90%;
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-link {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: var(--accent-gradient);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
}

.logo-icon svg {
  fill: white;
  width: 18px;
  height: 18px;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition-fast);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background: var(--glass-highlight);
}

/* メインコンテンツ */
main {
  flex: 1;
  width: 90%;
  max-width: 1600px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

/* ヒーローセクション */
.hero {
  text-align: left;
  margin-bottom: 2rem;
  animation: fadeIn 0.8s ease-out;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.hero-title {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.5px;
  color: var(--text-primary);
  margin: 0;
}

.hero-title span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  max-width: 600px;
  margin-top: 0.25rem;
}

.hero-meta {
  display: flex;
  align-items: flex-start;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  line-height: 1.4;
}

.hero-meta svg {
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--accent-primary);
}

/* 検索 & フィルター */
.search-filter-section {
  margin-bottom: 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.search-wrapper {
  position: relative;
  max-width: 600px;
  width: 100%;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: 1rem 1.5rem 1rem 3.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 1.05rem;
  transition: var(--transition-normal);
  outline: none;
  box-shadow: var(--shadow-sm);
}

.search-input:focus {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-glow);
  background: var(--bg-tertiary);
}

.search-icon {
  position: absolute;
  left: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
  transition: var(--transition-fast);
}

.search-input:focus + .search-icon {
  color: var(--accent-primary);
}

.filter-categories {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.filter-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  padding: 0.5rem 1.25rem;
  border-radius: 50px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-normal);
}

.filter-btn:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.filter-btn.active {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  box-shadow: var(--shadow-glow);
}

/* カードグリッド */
.notes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
  opacity: 1;
  transition: opacity 0.3s ease;
}

.note-card {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
}

.note-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.note-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.note-card:hover::before {
  opacity: 1;
}

.note-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.25rem;
}

.note-category {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent-primary);
  background: hsla(210, 100%, 60%, 0.1);
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
}

.note-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.note-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
  line-height: 1.4;
}

.note-excerpt {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.25rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.note-footer {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--accent-primary);
  font-weight: 600;
  font-size: 0.9rem;
}

.note-footer svg {
  transition: transform var(--transition-fast);
}

.note-card:hover .note-footer svg {
  transform: translateX(4px);
}

/* 記事詳細ページ用スタイル */
.article-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 0;
}

.article-back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  margin-bottom: 2rem;
  transition: var(--transition-fast);
}

.article-back-link:hover {
  color: var(--accent-primary);
}

.article-header {
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--glass-border);
  padding-bottom: 2rem;
}

.article-title {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.3;
  margin-top: 0.5rem;
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  gap: 1.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.article-content {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-content h1, 
.article-content h2, 
.article-content h3 {
  color: var(--text-primary);
  font-weight: 700;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

.article-content h1 { font-size: 1.8rem; border-left: 4px solid var(--accent-primary); padding-left: 1rem; }
.article-content h2 { font-size: 1.5rem; }
.article-content h3 { font-size: 1.25rem; }

.article-content p {
  margin-bottom: 1.5rem;
  color: var(--text-secondary);
}

.article-content ul, 
.article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
  color: var(--text-secondary);
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-tertiary);
  padding: 0.2rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--accent-primary);
}

.article-content pre {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

.article-content pre code {
  background: transparent;
  padding: 0;
  color: var(--text-primary);
}

.article-content blockquote {
  border-left: 4px solid var(--accent-secondary);
  padding-left: 1.5rem;
  margin-left: 0;
  margin-right: 0;
  margin-bottom: 1.5rem;
  font-style: italic;
  color: var(--text-secondary);
}

.article-content a {
  color: var(--accent-primary);
  text-decoration: none;
  border-bottom: 1px dashed var(--accent-primary);
  transition: var(--transition-fast);
}

.article-content a:hover {
  color: var(--accent-secondary);
  border-bottom-style: solid;
}

/* フッター */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--glass-border);
  padding: 2.5rem 2rem;
  text-align: center;
  margin-top: auto;
}

.footer-container {
  width: 90%;
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.footer-logo {
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* アニメーション */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 「もっと見る」ボタン */
.load-more-container {
  display: flex;
  justify-content: center;
  margin-top: 3rem;
  animation: fadeIn var(--transition-normal);
}

.load-more-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  padding: 0.75rem 2.5rem;
  border-radius: 50px;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.load-more-btn:hover {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.load-more-btn:active {
  transform: translateY(0);
}

/* レスポンシブ調整 */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.25rem;
  }
  .header-container,
  main,
  .footer-container {
    width: 100%;
  }
  main {
    padding: 2rem 1.25rem;
  }
  .article-title {
    font-size: 2rem;
  }
}


/* テーブルの折り返し・レスポンシブ改善 */
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  table-layout: auto;
  word-break: break-all;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.article-content th,
.article-content td {
  padding: 0.75rem;
  border: 1px solid var(--glass-border);
  text-align: left;
  white-space: normal;
}

.article-content th {
  background: rgba(255, 255, 255, 0.05);
  font-weight: 600;
}

@media (max-width: 768px) {
  .article-content table:has(td[data-label]) thead {
    display: none;
  }
  
  .article-content table:has(td[data-label]) tr {
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    display: block;
    margin-bottom: 1rem;
    padding: 0.5rem;
    background: rgba(255, 255, 255, 0.02);
  }
  
  .article-content table:has(td[data-label]) td {
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0.5rem;
    text-align: right;
  }
  
  .article-content table:has(td[data-label]) td::before {
    content: attr(data-label);
    font-weight: bold;
    float: left;
    text-align: left;
    color: var(--text-muted);
    margin-right: 1rem;
  }
  
  .article-content table:has(td[data-label]) td:last-child {
    border-bottom: 0;
  }
}

/* Amazonアソシエイト埋め込み用のスタイル */
.amazon-embed-container {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 3rem 0;
  padding: 1.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

/* Amazonアソシエイトリンクのボタン用スタイル（URLのみが提供された場合のフォールバック用） */
.amazon-text-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: linear-gradient(135deg, #ff9900, #ffb300);
  color: #111 !important; /* 暗いテキスト */
  font-weight: 700;
  padding: 0.75rem 2rem;
  border-radius: 50px;
  text-decoration: none !important;
  border-bottom: none !important;
  box-shadow: 0 4px 12px rgba(255, 153, 0, 0.2);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.amazon-text-link-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(255, 153, 0, 0.4);
}

.amazon-text-link-btn:active {
  transform: translateY(0);
}

.amazon-text-link-btn svg {
  stroke: #111;
}

/* 免責事項テキスト */
.footer-disclaimer {
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-top: 0.5rem;
  line-height: 1.4;
}

/* Amazonアソシエイト埋め込み用のスタイル (代替案1用追加分) */
.amazon-text-card-content {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.75rem;
}

.amazon-text-card-content .product-badge {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent-secondary);
  background: hsla(260, 90%, 65%, 0.1);
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
}

.amazon-text-card-content .product-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.4;
}

.amazon-text-card-content .product-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0 0 0.5rem 0;
  max-width: 600px;
  line-height: 1.6;
}


/* ==========================================================================
   2カラムレイアウト（サイドバー）＆ ビュー切り替え用スタイル
   ========================================================================== */

/* 2カラムレイアウトレイアウト */
.main-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.5rem;
  align-items: start;
}

/* サイドバー */
.sidebar {
  position: sticky;
  top: 100px; /* ヘッダーの高さ＋余白 */
  max-height: calc(100vh - 140px); /* 画面内に収まるように最大高さを制限 */
  overflow-y: auto; /* サイドバー内のみで独立してスクロール可能に */
  scrollbar-width: thin; /* Firefox用：スクロールバーを細くする */
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  z-index: 10;
}

/* Webkit系（Chrome/Safari）用スクロールバーの微調整 */
.sidebar::-webkit-scrollbar {
  width: 4px;
}
.sidebar::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: var(--radius-sm);
}
.sidebar::-webkit-scrollbar-thumb:hover {
  background: var(--accent-primary);
}

.sidebar-toggle-header {
  display: none; /* デフォルト（PC）では非表示 */
}

.sidebar-content {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.sidebar-section-title {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

/* サイドバー内の検索窓調整 */
.sidebar .search-wrapper {
  max-width: 100%;
}

.sidebar .search-input {
  padding: 0.75rem 1rem 0.75rem 2.75rem;
  font-size: 0.95rem;
  border-radius: var(--radius-md);
}

.sidebar .search-icon {
  left: 1rem;
}

.sidebar .search-icon svg {
  width: 16px;
  height: 16px;
}

/* サイドバー内のカテゴリボタン */
.sidebar .filter-categories {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 0.5rem;
}

.sidebar .filter-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  padding: 0.6rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: var(--transition-fast);
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}

.sidebar .filter-btn:hover {
  background: var(--glass-highlight);
  color: var(--text-primary);
}

.sidebar .filter-btn.active {
  background: var(--accent-gradient);
  color: white;
  border-color: transparent;
  box-shadow: var(--shadow-glow);
}

/* カテゴリ件数バッジのスタイル */
.category-count {
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.15);
  color: inherit;
  padding: 0.15rem 0.5rem;
  border-radius: 20px;
  min-width: 20px;
  text-align: center;
}

.sidebar .filter-btn.active .category-count {
  background: rgba(255, 255, 255, 0.25);
}

/* ツールバー */
.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--glass-border);
}

.toolbar-info {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.toolbar-info span {
  font-weight: 700;
  color: var(--accent-primary);
}

.view-switchers {
  display: flex;
  gap: 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--glass-border);
  padding: 0.25rem;
  border-radius: var(--radius-sm);
}

.view-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  cursor: pointer;
  transition: var(--transition-fast);
}

.view-btn:hover {
  color: var(--text-primary);
  background: var(--glass-highlight);
}

.view-btn.active {
  color: var(--text-primary);
  background: var(--bg-tertiary);
  box-shadow: var(--shadow-sm);
}

/* ==========================================================================
   リストビュー用スタイル
   ========================================================================== */

.notes-grid.list-view {
  grid-template-columns: 1fr;
  gap: 1rem;
}

.notes-grid.list-view .note-card {
  padding: 1.25rem 1.5rem;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.notes-grid.list-view .note-card::before {
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
}

.notes-grid.list-view .note-card > div:first-child {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex: 1;
}

.notes-grid.list-view .note-header {
  margin-bottom: 0;
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 1rem;
  width: 180px; /* 固定幅を持たせて揃える */
  flex-shrink: 0;
}

.notes-grid.list-view .note-date {
  font-size: 0.8rem;
  white-space: nowrap;
}

.notes-grid.list-view .note-title {
  font-size: 1.1rem;
  margin-bottom: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
}

.notes-grid.list-view .note-excerpt {
  display: none; /* リストビューでは概要文を非表示にしてスッキリさせる */
}

.notes-grid.list-view .note-footer {
  font-size: 0.85rem;
  white-space: nowrap;
}

/* ==========================================================================
   レスポンシブ対応（スマホ画面）
   ========================================================================== */

@media (max-width: 768px) {
  .main-layout {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  .hero {
    order: -1; /* スマホではヒーロー（タイトル）を一番上に配置 */
    text-align: center;
    margin-bottom: 1.5rem;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p {
    margin: 0 auto;
  }

  /* スマホでのサイドバー（折りたたみアコーディオン） */
  .sidebar {
    position: static;
    padding: 0;
    max-height: none; /* PC用の高さ制限を解除 */
    overflow: hidden; /* アコーディオンのアニメーション用 */
  }

  .sidebar-toggle-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    cursor: pointer;
    background: var(--bg-secondary);
  }

  .sidebar-toggle-title {
    font-size: 0.95rem;
    font-weight: 700;
  }

  .sidebar-toggle-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    cursor: pointer;
    transition: transform var(--transition-normal);
  }

  .sidebar-content {
    display: none; /* 初期状態では非表示 */
    padding: 1rem 1.25rem 1.5rem;
    border-top: 1px solid var(--glass-border);
    animation: slideDown 0.3s ease-out forwards;
  }

  /* 開閉状態の制御用クラス */
  .sidebar.open .sidebar-content {
    display: flex;
  }

  .sidebar.open .sidebar-toggle-btn {
    transform: rotate(180deg);
  }

  .sidebar .filter-categories {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.5rem;
  }

  .sidebar .filter-btn {
    width: auto;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    border: 1px solid var(--glass-border);
    background: var(--bg-secondary);
  }

  .sidebar .filter-btn.active {
    border-color: transparent;
  }

  /* スマホでのリスト表示調整 */
  .notes-grid.list-view .note-card {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  .notes-grid.list-view .note-card > div:first-child {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    width: 100%;
  }

  .notes-grid.list-view .note-header {
    width: 100%;
    justify-content: space-between;
  }

  .notes-grid.list-view .note-title {
    white-space: normal;
    overflow: visible;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }

  .notes-grid.list-view .note-footer {
    align-self: flex-end;
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================================================
   個別記事ナビゲーション＆関連記事
   ========================================================================== */

.article-nav-section {
  margin-top: 4rem;
  border-top: 1px solid var(--glass-border);
  padding-top: 3rem;
  display: flex;
  flex-direction: column;
  gap: 3.5rem;
}

/* 前後の記事 */
.article-prev-next {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.nav-card {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 1.25rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.nav-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-sm), var(--shadow-glow);
}

.prev-card {
  text-align: left;
}

.next-card {
  text-align: right;
  align-items: flex-end;
}

.nav-direction {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: flex;
  align-items: center;
}

.nav-card:hover .nav-direction {
  color: var(--accent-primary);
}

.nav-title {
  font-size: 0.9rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.nav-card-empty {
  visibility: hidden;
}

/* 関連記事 */
.article-related {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.related-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
}

.related-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 1.25rem;
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  text-decoration: none;
  color: inherit;
  transition: transform var(--transition-normal), border-color var(--transition-normal);
  min-height: 140px;
}

.related-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent-primary);
}

.related-category {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent-primary);
  background: hsla(210, 100%, 60%, 0.1);
  padding: 0.15rem 0.5rem;
  border-radius: 50px;
  align-self: flex-start;
  margin-bottom: 0.5rem;
}

.related-card-title {
  font-size: 0.9rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.related-date {
  font-size: 0.75rem;
  color: var(--text-muted);
}

@media (max-width: 600px) {
  .article-prev-next {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .nav-card-empty {
    display: none;
  }
  .related-grid {
    grid-template-columns: 1fr;
  }
}