/* ===========================
   吹奏楽の杜 — メインスタイル
   =========================== */

/* --- CSS変数 --- */
:root {
  --forest-dark: #1a3a18;
  --forest-mid: #2d5a27;
  --forest-light: #4a8040;
  --wood-dark: #5c3317;
  --wood-mid: #8b5e3c;
  --wood-light: #c4956a;
  --gold: #c9a84c;
  --gold-light: #e5c876;
  --cream: #f7f2e8;
  --cream-dark: #ece5d4;
  --white: #fefcf8;
  --text-dark: #1a100a;
  --text-mid: #4a3728;
  --text-light: #7a6555;
  --woodwind-color: #2d6b3f;
  --brass-color: #8b5e00;
  --perc-color: #5c2d91;
  --ensemble-color: #1a3a6b;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.16);
  --radius: 10px;
  --radius-sm: 6px;
  --transition: 0.25s ease;
}

/* --- リセット & ベース --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP", Meiryo, "游ゴシック体", YuGothic, sans-serif;
  background: var(--cream);
  color: var(--text-dark);
  line-height: 1.75;
  font-size: 16px;
}

h1, h2, h3, h4 {
  font-family: "Hiragino Mincho ProN", "Hiragino Mincho Pro", "Yu Mincho", "游明朝体", YuMincho, serif;
  line-height: 1.4;
  color: var(--forest-dark);
}

a { color: var(--forest-mid); text-decoration: none; }
a:hover { color: var(--forest-light); }

img { max-width: 100%; }

/* --- レイアウト --- */
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

.section-title {
  font-size: 1.8rem;
  margin-bottom: 0.4em;
  color: var(--forest-dark);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60%;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), transparent);
  margin-top: 6px;
  border-radius: 2px;
}

.section-lead {
  color: var(--text-mid);
  font-size: 1rem;
  margin-bottom: 2.5rem;
  max-width: 640px;
}

/* --- ナビゲーション --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--forest-dark);
  box-shadow: 0 2px 12px rgba(0,0,0,0.3);
}

.nav-container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 64px;
  gap: 32px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--gold-light);
  font-family: "Hiragino Mincho ProN", "Hiragino Mincho Pro", "Yu Mincho", YuMincho, serif;
  font-size: 1.25rem;
  font-weight: 700;
  white-space: nowrap;
  flex-shrink: 0;
}

.logo-icon {
  font-size: 1.5rem;
  color: var(--gold);
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 4px;
  align-items: center;
  flex: 1;
}

.nav-menu > li > a {
  color: rgba(255,255,255,0.85);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-menu > li > a:hover,
.nav-menu > li.active > a {
  color: var(--gold-light);
  background: rgba(255,255,255,0.08);
}

.caret { font-size: 0.7em; }

/* ドロップダウン */
.nav-dropdown { position: relative; }

.dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--forest-dark);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  list-style: none;
  min-width: 160px;
  padding: 6px 0;
  box-shadow: var(--shadow-lg);
  z-index: 100;
}

.nav-dropdown:hover .dropdown-menu,
.nav-dropdown.open .dropdown-menu { display: block; }

.dropdown-menu li a {
  color: rgba(255,255,255,0.8);
  padding: 8px 18px;
  display: block;
  font-size: 0.875rem;
  transition: var(--transition);
}

.dropdown-menu li a:hover {
  color: var(--gold-light);
  background: rgba(255,255,255,0.06);
}

/* ハンバーガーボタン */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  margin-left: auto;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: rgba(255,255,255,0.8);
  border-radius: 2px;
  transition: var(--transition);
}

/* --- ヒーローセクション（ホーム） --- */
.hero {
  background: linear-gradient(135deg, var(--forest-dark) 0%, var(--forest-mid) 60%, #3d6b35 100%);
  padding: 80px 24px 90px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '♩ ♪ ♫ ♬';
  position: absolute;
  top: 20px;
  right: 40px;
  font-size: 4rem;
  opacity: 0.07;
  color: white;
  letter-spacing: 12px;
}

.hero-badge {
  display: inline-block;
  background: rgba(201,168,76,0.2);
  border: 1px solid var(--gold);
  color: var(--gold-light);
  font-size: 0.8rem;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 20px;
  letter-spacing: 0.1em;
}

.hero-title {
  font-size: 3rem;
  color: white;
  margin-bottom: 0.3em;
  text-shadow: 0 2px 12px rgba(0,0,0,0.3);
}

.hero-title .yomi {
  font-size: 1.1rem;
  color: rgba(255,255,255,0.6);
  display: block;
  font-family: "Hiragino Kaku Gothic ProN", sans-serif;
  font-weight: normal;
  letter-spacing: 0.15em;
  margin-bottom: 0.5rem;
}

.hero-desc {
  color: rgba(255,255,255,0.75);
  font-size: 1.05rem;
  max-width: 560px;
  margin: 16px auto 36px;
  line-height: 1.8;
}

.hero-nav {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.hero-btn {
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  letter-spacing: 0.03em;
}

.hero-btn.woodwind {
  background: var(--woodwind-color);
  color: white;
  border: 2px solid rgba(255,255,255,0.2);
}

.hero-btn.brass {
  background: var(--brass-color);
  color: white;
  border: 2px solid rgba(255,255,255,0.2);
}

.hero-btn.perc {
  background: var(--perc-color);
  color: white;
  border: 2px solid rgba(255,255,255,0.2);
}

.hero-btn.ensemble {
  background: var(--ensemble-color);
  color: white;
  border: 2px solid rgba(255,255,255,0.2);
}

.hero-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
  color: white;
}

/* --- セクション共通 --- */
.section {
  padding: 64px 24px;
}

.section:nth-child(even) { background: var(--white); }
.section:nth-child(odd) { background: var(--cream); }

/* --- 楽器カードグリッド --- */
.section-header {
  display: flex;
  align-items: flex-end;
  gap: 20px;
  margin-bottom: 2rem;
}

.section-category-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.badge-woodwind {
  background: rgba(45,107,63,0.12);
  color: var(--woodwind-color);
  border: 1px solid rgba(45,107,63,0.25);
}

.badge-brass {
  background: rgba(139,94,0,0.12);
  color: var(--brass-color);
  border: 1px solid rgba(139,94,0,0.25);
}

.badge-perc {
  background: rgba(92,45,145,0.12);
  color: var(--perc-color);
  border: 1px solid rgba(92,45,145,0.25);
}

.badge-ensemble {
  background: rgba(26,58,107,0.12);
  color: var(--ensemble-color);
  border: 1px solid rgba(26,58,107,0.25);
}

.instrument-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.instrument-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: 28px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 12px;
  border: 1px solid rgba(0,0,0,0.06);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.instrument-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  border-radius: var(--radius) var(--radius) 0 0;
}

.instrument-card.woodwind::before { background: linear-gradient(90deg, var(--woodwind-color), #5aad6f); }
.instrument-card.brass::before { background: linear-gradient(90deg, var(--brass-color), #d4a017); }
.instrument-card.perc::before { background: linear-gradient(90deg, var(--perc-color), #9b72cf); }
.instrument-card.ensemble::before { background: linear-gradient(90deg, var(--ensemble-color), #3d78d4); }

.instrument-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.instrument-card:hover .card-arrow { transform: translateX(4px); }

.card-icon {
  font-size: 2.2rem;
  line-height: 1;
}

.card-title {
  font-size: 1.3rem;
  color: var(--forest-dark);
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
}

.card-subtitle {
  font-size: 0.8rem;
  color: var(--text-light);
  letter-spacing: 0.08em;
}

.card-desc {
  color: var(--text-mid);
  font-size: 0.875rem;
  line-height: 1.7;
  flex: 1;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 4px;
}

.card-meta {
  font-size: 0.78rem;
  color: var(--text-light);
}

.card-arrow {
  color: var(--gold);
  font-size: 1.1rem;
  transition: var(--transition);
}

/* --- 楽器詳細ページ ヒーロー --- */
.page-hero {
  padding: 52px 24px 56px;
  position: relative;
  overflow: hidden;
}

.page-hero.woodwind { background: linear-gradient(135deg, #1a3a24, var(--woodwind-color)); }
.page-hero.brass { background: linear-gradient(135deg, #3a2400, var(--brass-color)); }
.page-hero.perc { background: linear-gradient(135deg, #2d1045, var(--perc-color)); }
.page-hero.ensemble { background: linear-gradient(135deg, #0d1f40, var(--ensemble-color)); }

.page-hero::after {
  content: attr(data-note);
  position: absolute;
  right: 80px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 8rem;
  opacity: 0.08;
  color: white;
  font-family: serif;
  pointer-events: none;
  line-height: 1;
}

.page-hero-content { max-width: 1160px; margin: 0 auto; }

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.6);
}

.breadcrumb a { color: rgba(255,255,255,0.6); text-decoration: none; }
.breadcrumb a:hover { color: rgba(255,255,255,0.9); }
.breadcrumb-sep { opacity: 0.5; }

.page-hero-title {
  font-size: 2.6rem;
  color: white;
  margin-bottom: 0.2em;
}

.page-hero-en {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.1em;
  margin-bottom: 16px;
  font-family: Georgia, serif;
  font-style: italic;
}

.page-hero-desc {
  color: rgba(255,255,255,0.78);
  font-size: 1rem;
  max-width: 600px;
  line-height: 1.85;
}

/* --- コンテンツ本文 --- */
.page-content {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- 練習ポイントセクション --- */
.practice-section {
  padding: 52px 24px;
  background: var(--white);
}

.practice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 28px;
}

.practice-card {
  background: var(--cream);
  border-radius: var(--radius);
  padding: 24px;
  border-left: 4px solid var(--gold);
}

.practice-card-title {
  font-size: 1.05rem;
  color: var(--forest-dark);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.practice-card-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--gold);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.practice-card p {
  color: var(--text-mid);
  font-size: 0.88rem;
  line-height: 1.75;
}

/* --- 練習ポイントリスト --- */
.point-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 20px;
}

.point-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--white);
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.point-list .point-num {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--forest-mid);
  color: white;
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-weight: 700;
}

.point-list .point-body strong {
  display: block;
  color: var(--forest-dark);
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.point-list .point-body span {
  color: var(--text-mid);
  font-size: 0.85rem;
  line-height: 1.65;
}

/* --- 練習時間目安 --- */
.time-table {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.time-card {
  background: var(--cream);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  border: 1px solid var(--cream-dark);
}

.time-card .time-level {
  font-size: 0.82rem;
  color: var(--text-light);
  margin-bottom: 8px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.time-card .time-value {
  font-size: 1.6rem;
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
  color: var(--forest-dark);
  font-weight: 700;
  line-height: 1;
}

.time-card .time-unit {
  font-size: 0.78rem;
  color: var(--text-mid);
  margin-top: 4px;
}

/* --- 教材セクション (PDFリンク) --- */
.materials-section {
  padding: 52px 24px;
  background: var(--cream);
}

.level-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.level-tab {
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
  background: var(--white);
  color: var(--text-mid);
}

.level-tab:hover,
.level-tab.active {
  background: var(--forest-mid);
  color: white;
}

.pdf-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}

.pdf-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(0,0,0,0.07);
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: var(--transition);
}

.pdf-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.pdf-card-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.pdf-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: #e74c3c;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
  letter-spacing: 0.02em;
}

.pdf-card-title {
  font-size: 1rem;
  color: var(--forest-dark);
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
  line-height: 1.4;
}

.pdf-card-sub {
  font-size: 0.78rem;
  color: var(--text-light);
  margin-top: 2px;
}

.pdf-card-desc {
  font-size: 0.85rem;
  color: var(--text-mid);
  line-height: 1.7;
  flex: 1;
}

.pdf-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.pdf-tag {
  font-size: 0.75rem;
  padding: 2px 10px;
  border-radius: 12px;
  background: var(--cream);
  color: var(--text-mid);
  border: 1px solid var(--cream-dark);
}

.pdf-download-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--forest-mid);
  color: white;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  margin-top: auto;
}

.pdf-download-btn:hover {
  background: var(--forest-dark);
  color: white;
  transform: none;
}

.pdf-download-btn.brass-btn { background: var(--brass-color); }
.pdf-download-btn.brass-btn:hover { background: var(--wood-dark); }

.pdf-download-btn.perc-btn { background: var(--perc-color); }
.pdf-download-btn.perc-btn:hover { background: #3d1a60; }

.pdf-download-btn.ensemble-btn { background: var(--ensemble-color); }
.pdf-download-btn.ensemble-btn:hover { background: #0d1f40; }

/* --- 研究レポートリンク --- */
.report-link-section {
  padding: 40px 24px;
  background: var(--forest-dark);
  text-align: center;
}

.report-link-section h3 {
  color: var(--gold-light);
  font-size: 1.3rem;
  margin-bottom: 10px;
}

.report-link-section p {
  color: rgba(255,255,255,0.65);
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.report-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--gold);
  color: var(--gold-light);
  padding: 10px 24px;
  border-radius: 6px;
  font-size: 0.9rem;
  text-decoration: none;
  transition: var(--transition);
}

.report-btn:hover {
  background: var(--gold);
  color: var(--forest-dark);
}

/* --- 特徴セクション (ホーム) --- */
.features-section {
  padding: 64px 24px;
  background: var(--forest-dark);
}

.features-title { color: var(--gold-light); margin-bottom: 0.3em; }
.features-lead { color: rgba(255,255,255,0.6); margin-bottom: 2.5rem; }

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.feature-item {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius);
  padding: 24px;
}

.feature-item .fi-icon {
  font-size: 2rem;
  margin-bottom: 14px;
  display: block;
}

.feature-item h4 {
  color: var(--gold-light);
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.feature-item p {
  color: rgba(255,255,255,0.6);
  font-size: 0.875rem;
  line-height: 1.75;
}

/* --- フッター --- */
.site-footer {
  background: #0f1f0d;
  padding: 48px 24px 32px;
  color: rgba(255,255,255,0.55);
}

.footer-container {
  max-width: 1160px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-brand .logo-text {
  color: var(--gold-light);
  font-size: 1.3rem;
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
  display: block;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.82rem;
  line-height: 1.8;
}

.footer-nav-groups {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.footer-nav-group h4 {
  color: rgba(255,255,255,0.8);
  font-size: 0.85rem;
  margin-bottom: 12px;
  font-family: "Hiragino Kaku Gothic ProN", sans-serif;
  letter-spacing: 0.05em;
}

.footer-nav-group ul { list-style: none; display: flex; flex-direction: column; gap: 6px; }

.footer-nav-group a {
  color: rgba(255,255,255,0.45);
  font-size: 0.82rem;
  text-decoration: none;
  transition: var(--transition);
}

.footer-nav-group a:hover { color: rgba(255,255,255,0.8); }

.footer-bottom {
  max-width: 1160px;
  margin: 0 auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.08);
  font-size: 0.78rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

/* --- テーブル（合奏ページなど） --- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin: 20px 0;
}

.data-table th {
  background: var(--forest-dark);
  color: white;
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
  font-size: 0.82rem;
  letter-spacing: 0.03em;
}

.data-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--cream-dark);
  color: var(--text-mid);
  vertical-align: top;
}

.data-table tr:nth-child(even) td { background: var(--cream); }
.data-table tr:hover td { background: rgba(45,90,39,0.05); }

.data-table td:first-child {
  font-weight: 600;
  color: var(--forest-dark);
  white-space: nowrap;
}

.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--cream-dark);
}

/* --- タイムライン --- */
.timetable {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin-top: 24px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.tt-item {
  display: grid;
  grid-template-columns: 90px 1fr;
  border-bottom: 1px solid var(--cream-dark);
  background: var(--white);
}

.tt-item:last-child { border-bottom: none; }

.tt-time {
  background: var(--forest-dark);
  color: var(--gold-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 14px 12px;
  text-align: center;
  line-height: 1.4;
}

.tt-content {
  padding: 14px 20px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.tt-label {
  font-weight: 700;
  color: var(--forest-dark);
  font-size: 0.95rem;
}

.tt-note {
  color: var(--text-mid);
  font-size: 0.82rem;
}

/* --- レスポンシブ --- */
@media (max-width: 768px) {
  .hero-title { font-size: 2.2rem; }
  .page-hero-title { font-size: 2rem; }
  .section-title { font-size: 1.5rem; }

  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--forest-dark);
    padding: 16px 0;
    gap: 0;
    z-index: 999;
    border-top: 1px solid rgba(255,255,255,0.1);
  }

  .nav-menu.open { display: flex; }

  .nav-menu > li > a { border-radius: 0; padding: 12px 24px; }

  .dropdown-menu {
    position: static;
    display: none;
    box-shadow: none;
    border: none;
    border-top: 1px solid rgba(255,255,255,0.07);
    border-radius: 0;
    background: rgba(0,0,0,0.2);
    padding: 4px 0;
  }

  .nav-dropdown.open .dropdown-menu { display: block; }

  .dropdown-menu li a { padding: 10px 40px; }

  .nav-toggle { display: flex; }

  .footer-container { grid-template-columns: 1fr; gap: 28px; }
  .footer-nav-groups { grid-template-columns: 1fr 1fr; }

  .page-hero::after { display: none; }

  .tt-item { grid-template-columns: 70px 1fr; }

  .hero-nav { gap: 10px; }
  .hero-btn { padding: 10px 20px; font-size: 0.88rem; }
}

@media (max-width: 480px) {
  .hero { padding: 56px 20px 64px; }
  .section { padding: 44px 20px; }
  .instrument-grid { grid-template-columns: 1fr; }
  .footer-nav-groups { grid-template-columns: 1fr; }
  .time-table { grid-template-columns: 1fr 1fr; }
}

/* --- リンク集ページ --- */
.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.links-grid--featured {
  grid-template-columns: 1fr;
}

.link-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 20px 22px;
  border: 1px solid rgba(0,0,0,0.07);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: var(--transition);
}

.link-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.link-card-title {
  font-family: "Hiragino Mincho ProN", "Hiragino Mincho Pro", "Yu Mincho", YuMincho, serif;
  font-size: 1rem;
  color: var(--forest-dark);
}

.link-card-title a {
  color: var(--forest-dark);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.link-card-title a::after {
  content: '↗';
  font-size: 0.78em;
  color: var(--gold);
  font-family: sans-serif;
  flex-shrink: 0;
}

.link-card-title a:hover { color: var(--forest-light); }

.link-card-desc {
  font-size: 0.855rem;
  color: var(--text-mid);
  line-height: 1.72;
}

.link-card-domain {
  font-size: 0.74rem;
  color: var(--text-light);
  font-family: "Courier New", monospace;
  margin-top: 2px;
}

.link-featured {
  background: linear-gradient(135deg, rgba(26,58,24,0.04), rgba(201,168,76,0.07));
  border: 1px solid rgba(201,168,76,0.3);
  padding: 24px 28px;
}

.link-featured .link-card-title {
  font-size: 1.15rem;
}

@media (max-width: 600px) {
  .links-grid { grid-template-columns: 1fr; }
}

/* --- ユーティリティ --- */
.text-center { text-align: center; }
.mb-0 { margin-bottom: 0; }
.mt-32 { margin-top: 32px; }
.divider {
  border: none;
  border-top: 1px solid var(--cream-dark);
  margin: 40px 0;
}

/* スクロールアニメーション */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===========================
   エンゲージメント施策
   =========================== */

/* --- この記事でわかること --- */
.summary-wrap {
  background: var(--white);
  padding: 28px 24px 0;
  max-width: 1160px;
  margin: 0 auto;
}

.summary-box {
  background: linear-gradient(135deg, #eef7ee 0%, #e4f0e4 100%);
  border: 1px solid #b6d9b6;
  border-left: 5px solid var(--forest-mid);
  border-radius: var(--radius);
  padding: 18px 22px 16px;
}

.summary-box-title {
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--forest-dark);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 7px;
}

.summary-box ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 5px 20px;
}

.summary-box ul li {
  color: var(--text-mid);
  font-size: 0.875rem;
  padding-left: 1.4em;
  position: relative;
  line-height: 1.5;
}

.summary-box ul li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--forest-mid);
  font-weight: 700;
}

/* --- 目次 (TOC) --- */
.toc-box {
  background: var(--cream-dark);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 20px 0 0;
}

.toc-title {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-mid);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
  letter-spacing: 0.04em;
}

.toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.toc-list li a {
  display: inline-block;
  padding: 4px 12px;
  background: var(--white);
  border: 1px solid #c8b89a;
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-mid);
  transition: all var(--transition);
  text-decoration: none;
}

.toc-list li a:hover {
  background: var(--forest-mid);
  color: var(--cream);
  border-color: var(--forest-mid);
}

/* --- あわせて読みたい --- */
.related-box {
  background: var(--cream-dark);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-top: 36px;
}

.related-box-title {
  font-family: "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--forest-dark);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.related-links a {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 8px 16px;
  background: var(--white);
  border: 1.5px solid #c8b89a;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--text-dark);
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
  text-decoration: none;
}

.related-links a:hover {
  background: var(--forest-mid);
  color: var(--cream);
  border-color: var(--forest-mid);
  transform: translateY(-1px);
}

.related-links a .rel-arrow {
  font-size: 0.75rem;
  opacity: 0.65;
}

@media (max-width: 600px) {
  .summary-box ul {
    grid-template-columns: 1fr;
  }
  .toc-list, .related-links {
    gap: 6px;
  }
}