/* ==========================================
   最悪の世代・奇跡の世代 - メインスタイル
   frontend-design SKILL準拠
   ========================================== */

/* Google Fonts - 個性的なフォント選択 */
@import url('https://fonts.googleapis.com/css2?family=Zen+Maru+Gothic:wght@400;500;700&family=Shippori+Mincho:wght@400;600;700&family=Cormorant+Garamond:ital,wght@0,400;0,600;1,400&display=swap');

/* カスタムプロパティ - ナチュラルラベンダー */
:root {
  /* 個性的なフォント */
  --font-display: 'Shippori Mincho', 'Yu Mincho', serif;
  --font-body: 'Zen Maru Gothic', 'Hiragino Maru Gothic ProN', sans-serif;
  --font-accent: 'Cormorant Garamond', serif;

  /* くすみカラーパレット */
  --primary-lavender: #A99ABF;
  --primary-rose: #C9A9A6;
  --primary-sage: #A8B5A0;
  --primary-cream: #E8DFD4;
  --primary-greige: #9A9189;

  --accent-plum: #8B7A94;
  --accent-terracotta: #B89A8A;
  --accent-olive: #8A9A7A;

  /* グラデーション */
  --gradient-main: linear-gradient(135deg, #B8A9C9 0%, #C9B9A9 50%, #A9B9A9 100%);
  --gradient-hero: linear-gradient(160deg, #A99ABF 0%, #B8A9C9 30%, #C9B9A9 70%, #A9B9A9 100%);
  --gradient-warm: linear-gradient(135deg, #D4C4B4 0%, #C9A9A6 100%);
  --gradient-cool: linear-gradient(135deg, #A9B9A9 0%, #99A9B9 100%);

  /* テキスト */
  --text-dark: #3D3A38;
  --text-medium: #5A5550;
  --text-light: #8A8580;

  /* 背景 */
  --bg-cream: #FAF7F4;
  --bg-card: #FFFFFF;
  --bg-warm: #F5F0EB;

  /* シャドウ - より深みのある表現 */
  --shadow-soft: 0 2px 15px rgba(139, 122, 148, 0.08), 0 1px 3px rgba(139, 122, 148, 0.05);
  --shadow-medium: 0 8px 30px rgba(139, 122, 148, 0.12), 0 2px 8px rgba(139, 122, 148, 0.08);
  --shadow-strong: 0 20px 60px rgba(139, 122, 148, 0.15), 0 8px 20px rgba(139, 122, 148, 0.1);
  --shadow-glow: 0 0 40px rgba(184, 169, 201, 0.3);

  /* ボーダー */
  --border-radius-sm: 6px;
  --border-radius-md: 12px;
  --border-radius-lg: 20px;
  --border-radius-xl: 28px;

  /* アニメーション */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out-back: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 0.2s;
  --duration-normal: 0.4s;
  --duration-slow: 0.8s;
}

/* ノイズテクスチャ（SVG埋め込み） */
.noise-overlay::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  opacity: 0.03;
  pointer-events: none;
  z-index: 1;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--bg-cream);
  color: var(--text-dark);
  line-height: 1.9;
  min-height: 100vh;
  letter-spacing: 0.02em;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  position: relative;
}

/* 背景のテクスチャ */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 40%, rgba(184, 169, 201, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(201, 169, 166, 0.06) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* ============================================
   ヘッダー
   ============================================ */
.header {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid rgba(169, 154, 191, 0.1);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-dark);
}

.logo-icon {
  font-size: 1.75rem;
  filter: drop-shadow(0 2px 4px rgba(139, 122, 148, 0.2));
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.logo-text span {
  display: block;
  font-family: var(--font-accent);
  font-size: 0.65rem;
  font-weight: 400;
  color: var(--text-light);
  letter-spacing: 0.15em;
  margin-top: 2px;
}

.nav-menu {
  display: flex;
  gap: 0.5rem;
  list-style: none;
}

.nav-menu a {
  color: var(--text-medium);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.6rem 1.2rem;
  border-radius: var(--border-radius-sm);
  transition: all var(--duration-fast) var(--ease-out-expo);
  position: relative;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0.4rem;
  left: 50%;
  width: 0;
  height: 1px;
  background: var(--primary-lavender);
  transition: all var(--duration-normal) var(--ease-out-expo);
  transform: translateX(-50%);
}

.nav-menu a:hover {
  color: var(--accent-plum);
}

.nav-menu a:hover::after {
  width: 60%;
}

/* ハンバーガーメニュー */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 10px;
}

.hamburger span {
  width: 22px;
  height: 2px;
  background: var(--text-medium);
  border-radius: 2px;
  transition: all var(--duration-fast) var(--ease-out-expo);
}

/* ============================================
   ヒーローセクション
   ============================================ */
.hero {
  background: var(--gradient-hero);
  padding: 5rem 2rem 7rem;
  text-align: center;
  color: white;
  position: relative;
  overflow: hidden;
}

/* 装飾的な背景要素 */
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.15) 0%, transparent 40%),
    radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 30%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 100px;
  background: linear-gradient(to top, var(--bg-cream) 0%, transparent 100%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  margin: 0 auto;
  animation: heroFadeIn 1.2s var(--ease-out-expo) forwards;
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 5vw, 2.75rem);
  font-weight: 600;
  margin-bottom: 1.25rem;
  line-height: 1.4;
  letter-spacing: 0.05em;
  text-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.hero p {
  font-size: 1rem;
  opacity: 0.92;
  margin-bottom: 2rem;
  line-height: 2;
  animation: heroFadeIn 1.2s var(--ease-out-expo) 0.2s both;
}

/* ============================================
   年代選択グリッド
   ============================================ */
.year-selector {
  max-width: 1200px;
  margin: -4rem auto 4rem;
  padding: 0 1.5rem;
  position: relative;
  z-index: 10;
}

.decade-section {
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  padding: 2.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
  animation: sectionReveal 0.8s var(--ease-out-expo) both;
}

.decade-section:nth-child(1) { animation-delay: 0.1s; }
.decade-section:nth-child(2) { animation-delay: 0.15s; }
.decade-section:nth-child(3) { animation-delay: 0.2s; }
.decade-section:nth-child(4) { animation-delay: 0.25s; }
.decade-section:nth-child(5) { animation-delay: 0.3s; }
.decade-section:nth-child(6) { animation-delay: 0.35s; }
.decade-section:nth-child(7) { animation-delay: 0.4s; }
.decade-section:nth-child(8) { animation-delay: 0.45s; }

@keyframes sectionReveal {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 装飾的なアクセント */
.decade-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--gradient-main);
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out-expo);
}

.decade-section:hover::before {
  opacity: 1;
}

.decade-title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: 1.75rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(169, 154, 191, 0.15);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--text-dark);
}

.decade-title::before {
  content: '✦';
  font-size: 0.9rem;
  color: var(--primary-lavender);
}

.year-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(95px, 1fr));
  gap: 1rem;
}

.year-card {
  background: var(--bg-card);
  border: 1px solid rgba(169, 154, 191, 0.12);
  border-radius: var(--border-radius-md);
  padding: 1.1rem 0.75rem;
  text-align: center;
  text-decoration: none;
  color: var(--text-dark);
  font-weight: 600;
  transition: all var(--duration-normal) var(--ease-out-back);
  position: relative;
  overflow: hidden;
}

.year-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-main);
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out-expo);
}

.year-card::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: all var(--duration-slow) var(--ease-out-expo);
}

.year-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-medium), var(--shadow-glow);
  border-color: transparent;
}

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

.year-card:hover::after {
  width: 200%;
  height: 200%;
  opacity: 0;
}

.year-card .year {
  font-family: var(--font-accent);
  font-size: 1.4rem;
  font-weight: 600;
  display: block;
  position: relative;
  z-index: 1;
  transition: color var(--duration-normal) var(--ease-out-expo);
}

.year-card .era {
  font-family: var(--font-body);
  font-size: 0.65rem;
  color: var(--text-light);
  margin-top: 0.35rem;
  position: relative;
  z-index: 1;
  letter-spacing: 0.02em;
  transition: color var(--duration-normal) var(--ease-out-expo);
}

.year-card:hover .year,
.year-card:hover .era {
  color: white;
}

/* ============================================
   記事ページ
   ============================================ */
.article-container {
  max-width: 880px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

.article-header {
  background: var(--gradient-hero);
  color: white;
  padding: 4rem 3rem;
  border-radius: var(--border-radius-xl);
  margin-bottom: 2.5rem;
  text-align: center;
  box-shadow: var(--shadow-strong);
  position: relative;
  overflow: hidden;
  animation: articleHeaderReveal 1s var(--ease-out-expo) forwards;
}

@keyframes articleHeaderReveal {
  from {
    opacity: 0;
    transform: scale(0.95) translateY(20px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.article-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 0% 100%, rgba(255, 255, 255, 0.12) 0%, transparent 50%),
    radial-gradient(circle at 100% 0%, rgba(255, 255, 255, 0.08) 0%, transparent 40%);
}

.article-year {
  font-family: var(--font-accent);
  font-size: clamp(4rem, 12vw, 6rem);
  font-weight: 400;
  line-height: 1;
  position: relative;
  z-index: 1;
  letter-spacing: -0.02em;
}

.article-year span {
  font-family: var(--font-display);
  font-size: 0.35em;
  font-weight: 400;
  vertical-align: super;
  letter-spacing: 0.1em;
}

.article-title {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 4vw, 1.6rem);
  font-weight: 600;
  margin-top: 1.25rem;
  line-height: 1.5;
  letter-spacing: 0.04em;
  position: relative;
  z-index: 1;
}

.article-meta {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 1.75rem;
  font-size: 0.85rem;
  opacity: 0.9;
  position: relative;
  z-index: 1;
}

.article-meta span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-body);
}

/* 記事本文 */
.article-content {
  background: var(--bg-card);
  border-radius: var(--border-radius-lg);
  padding: 3.5rem;
  box-shadow: var(--shadow-soft);
  animation: contentReveal 0.8s var(--ease-out-expo) 0.3s both;
}

@keyframes contentReveal {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.article-content h2 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-dark);
  margin: 3rem 0 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--primary-lavender);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  letter-spacing: 0.03em;
  position: relative;
}

.article-content h2::before {
  content: '◆';
  font-size: 0.7rem;
  color: var(--primary-lavender);
}

.article-content h2:first-of-type {
  margin-top: 0;
}

.article-content h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent-plum);
  margin: 2.25rem 0 1rem;
  padding-left: 1rem;
  border-left: 3px solid var(--primary-lavender);
  letter-spacing: 0.02em;
}

.article-content p {
  margin-bottom: 1.75rem;
  text-align: justify;
  word-break: break-word;
}

.article-content ul, .article-content ol {
  margin: 1.25rem 0 2rem 1.5rem;
}

.article-content li {
  margin-bottom: 0.6rem;
}

/* ============================================
   ハイライトボックス
   ============================================ */
.highlight-box {
  background: var(--gradient-main);
  color: white;
  padding: 2rem 2.5rem;
  border-radius: var(--border-radius-md);
  margin: 2.5rem 0;
  font-weight: 500;
  position: relative;
  overflow: hidden;
  line-height: 2;
}

.highlight-box::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 150px;
  height: 150px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 50%;
  transform: translate(30%, -30%);
}

.info-box {
  background: linear-gradient(135deg, #F8F5F2 0%, #F5F2EE 100%);
  border-left: 4px solid var(--primary-lavender);
  padding: 1.75rem 2rem;
  border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
  margin: 2.5rem 0;
}

.warning-box {
  background: linear-gradient(135deg, #F8F2F0 0%, #F5EFED 100%);
  border-left: 4px solid var(--primary-rose);
  padding: 1.75rem 2rem;
  border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
  margin: 2.5rem 0;
}

/* ============================================
   特徴カード
   ============================================ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin: 2.5rem 0;
}

.feature-card {
  background: var(--bg-card);
  border-radius: var(--border-radius-md);
  padding: 2rem 1.75rem;
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(169, 154, 191, 0.08);
  transition: all var(--duration-normal) var(--ease-out-back);
  position: relative;
}

.feature-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background: var(--gradient-main);
  transition: all var(--duration-normal) var(--ease-out-expo);
  transform: translateX(-50%);
  border-radius: 3px 3px 0 0;
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-medium);
}

.feature-card:hover::after {
  width: 60%;
}

.feature-card-icon {
  font-size: 2.25rem;
  margin-bottom: 1rem;
  display: block;
}

.feature-card h4 {
  font-family: var(--font-display);
  color: var(--accent-plum);
  margin-bottom: 0.6rem;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-medium);
  line-height: 1.8;
}

/* ============================================
   有名人リスト
   ============================================ */
.celebrity-section {
  margin: 2.5rem 0;
}

.celebrity-month {
  margin-bottom: 2.5rem;
}

.celebrity-month h4 {
  background: var(--gradient-cool);
  color: white;
  padding: 0.7rem 1.5rem;
  border-radius: var(--border-radius-sm);
  margin-bottom: 1.25rem;
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.95rem;
  letter-spacing: 0.03em;
}

.celebrity-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.celebrity-tag {
  background: var(--bg-card);
  border: 1px solid var(--primary-sage);
  color: var(--text-dark);
  padding: 0.55rem 1.1rem;
  border-radius: 50px;
  font-size: 0.85rem;
  transition: all var(--duration-fast) var(--ease-out-expo);
  cursor: default;
}

.celebrity-tag:hover {
  background: var(--primary-sage);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}

/* ============================================
   年表
   ============================================ */
.timeline {
  position: relative;
  padding-left: 2.5rem;
  margin: 2.5rem 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--primary-lavender) 0%, var(--primary-rose) 50%, var(--primary-sage) 100%);
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  padding: 1.25rem 0 1.25rem 2rem;
  border-bottom: 1px dashed rgba(169, 154, 191, 0.2);
  transition: all var(--duration-fast) var(--ease-out-expo);
}

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

.timeline-item:hover {
  background: rgba(184, 169, 201, 0.03);
  border-radius: var(--border-radius-sm);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2.5rem;
  top: 1.5rem;
  width: 12px;
  height: 12px;
  background: var(--bg-card);
  border: 3px solid var(--primary-lavender);
  border-radius: 50%;
  transition: all var(--duration-fast) var(--ease-out-expo);
}

.timeline-item:hover::before {
  background: var(--primary-lavender);
  transform: scale(1.2);
}

.timeline-year {
  font-family: var(--font-accent);
  font-weight: 600;
  color: var(--accent-plum);
  font-size: 1.1rem;
}

.timeline-age {
  display: inline-block;
  background: var(--gradient-warm);
  color: white;
  padding: 0.2rem 0.7rem;
  border-radius: 50px;
  font-size: 0.75rem;
  margin-left: 0.6rem;
  font-weight: 500;
}

.timeline-content {
  margin-top: 0.5rem;
  color: var(--text-medium);
  font-size: 0.95rem;
}

/* ============================================
   占いセクション
   ============================================ */
.fortune-section {
  background: linear-gradient(135deg, #F8F5F2 0%, #F5F2EE 100%);
  border-radius: var(--border-radius-lg);
  padding: 2.5rem;
  margin: 2.5rem 0;
  position: relative;
}

.fortune-section::before {
  content: '';
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 80px;
  height: 80px;
  background: radial-gradient(circle, rgba(184, 169, 201, 0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.fortune-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.25rem;
}

.fortune-item {
  text-align: center;
  padding: 1.75rem 1.25rem;
  background: var(--bg-card);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-soft);
  transition: all var(--duration-normal) var(--ease-out-back);
}

.fortune-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-medium);
}

.fortune-icon {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
  display: block;
}

.fortune-label {
  font-size: 0.8rem;
  color: var(--text-light);
  margin-bottom: 0.35rem;
  letter-spacing: 0.05em;
}

.fortune-value {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent-plum);
  letter-spacing: 0.02em;
}

/* ============================================
   トレンドセクション
   ============================================ */
.trend-section {
  margin: 2.5rem 0;
}

.trend-category {
  margin-bottom: 2.25rem;
}

.trend-category h4 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
  color: var(--accent-plum);
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.trend-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.trend-item {
  background: var(--bg-card);
  border: 1px solid var(--primary-rose);
  padding: 0.5rem 1.15rem;
  border-radius: 50px;
  font-size: 0.85rem;
  transition: all var(--duration-fast) var(--ease-out-expo);
  cursor: default;
}

.trend-item:hover {
  background: var(--primary-rose);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-soft);
}

/* ============================================
   シェアボタン
   ============================================ */
.share-section {
  margin: 3.5rem 0;
  text-align: center;
}

.share-section h4 {
  margin-bottom: 1.25rem;
  color: var(--text-light);
  font-size: 0.9rem;
  letter-spacing: 0.05em;
}

.share-buttons {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}

.share-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  color: white;
  font-size: 1.15rem;
  text-decoration: none;
  transition: all var(--duration-normal) var(--ease-out-back);
  box-shadow: var(--shadow-soft);
}

.share-btn:hover {
  transform: translateY(-4px) scale(1.08);
  box-shadow: var(--shadow-medium);
}

.share-btn.twitter { background: #1DA1F2; }
.share-btn.facebook { background: #1877F2; }
.share-btn.line { background: #06C755; }

/* ============================================
   関連記事
   ============================================ */
.related-section {
  margin: 3.5rem 0;
}

.related-section h2 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  border-bottom: 2px solid var(--primary-lavender);
  padding-bottom: 0.75rem;
  margin-bottom: 1.5rem;
  letter-spacing: 0.03em;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.related-card {
  background: var(--bg-card);
  border-radius: var(--border-radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  text-decoration: none;
  color: var(--text-dark);
  transition: all var(--duration-normal) var(--ease-out-back);
}

.related-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-medium);
}

.related-card-header {
  background: var(--gradient-main);
  color: white;
  padding: 1.75rem;
  text-align: center;
}

.related-card-year {
  font-family: var(--font-accent);
  font-size: 2.25rem;
  font-weight: 400;
}

.related-card-body {
  padding: 1.25rem;
}

.related-card-title {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-medium);
}

/* ============================================
   フッター
   ============================================ */
.footer {
  background: var(--text-dark);
  color: rgba(255, 255, 255, 0.85);
  padding: 3.5rem 2rem 2rem;
  margin-top: 5rem;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-section h5 {
  font-family: var(--font-display);
  color: var(--primary-lavender);
  margin-bottom: 1.25rem;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
}

.footer-section ul {
  list-style: none;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  font-size: 0.85rem;
  display: block;
  padding: 0.35rem 0;
  transition: all var(--duration-fast) var(--ease-out-expo);
}

.footer-section a:hover {
  color: var(--primary-lavender);
  transform: translateX(4px);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.4);
  letter-spacing: 0.03em;
}

/* ============================================
   目次
   ============================================ */
.toc {
  background: linear-gradient(135deg, #F8F5F2 0%, #F5F2EE 100%);
  border-radius: var(--border-radius-md);
  padding: 1.75rem 2.25rem;
  margin: 2.5rem 0;
  border: 1px solid rgba(169, 154, 191, 0.1);
}

.toc h4 {
  font-family: var(--font-display);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  color: var(--accent-plum);
  font-size: 1rem;
  letter-spacing: 0.03em;
}

.toc ul {
  list-style: none;
  margin: 0;
}

.toc li {
  padding: 0.6rem 0;
  border-bottom: 1px dashed rgba(169, 154, 191, 0.15);
}

.toc li:last-child {
  border-bottom: none;
}

.toc a {
  color: var(--text-medium);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  transition: all var(--duration-fast) var(--ease-out-expo);
}

.toc a::before {
  content: '›';
  color: var(--primary-lavender);
  font-size: 1.1rem;
  transition: transform var(--duration-fast) var(--ease-out-expo);
}

.toc a:hover {
  color: var(--accent-plum);
}

.toc a:hover::before {
  transform: translateX(4px);
}

/* ============================================
   トップへ戻るボタン
   ============================================ */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  background: var(--gradient-main);
  color: white;
  border: none;
  border-radius: 50%;
  font-size: 1.25rem;
  cursor: pointer;
  box-shadow: var(--shadow-medium);
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-normal) var(--ease-out-back);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: var(--shadow-strong);
}

/* ============================================
   レスポンシブ
   ============================================ */
@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
  }

  .nav-menu {
    display: none;
    width: 100%;
    flex-direction: column;
    padding-top: 1rem;
    gap: 0.25rem;
  }

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

  .hamburger {
    display: flex;
  }

  .hero {
    padding: 3.5rem 1.5rem 5rem;
  }

  .hero h1 {
    font-size: 1.6rem;
  }

  .article-header {
    padding: 2.5rem 1.5rem;
  }

  .article-year {
    font-size: 3.5rem;
  }

  .article-title {
    font-size: 1.15rem;
  }

  .article-content {
    padding: 2rem 1.5rem;
  }

  .decade-section {
    padding: 1.75rem;
  }

  .year-grid {
    grid-template-columns: repeat(auto-fill, minmax(75px, 1fr));
    gap: 0.65rem;
  }

  .year-card {
    padding: 0.85rem 0.5rem;
  }

  .year-card .year {
    font-size: 1.15rem;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   アニメーション
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(25px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.7s var(--ease-out-expo) forwards;
}

/* Staggered reveal for elements */
.stagger-reveal > * {
  opacity: 0;
  animation: fadeInUp 0.6s var(--ease-out-expo) forwards;
}

.stagger-reveal > *:nth-child(1) { animation-delay: 0.1s; }
.stagger-reveal > *:nth-child(2) { animation-delay: 0.15s; }
.stagger-reveal > *:nth-child(3) { animation-delay: 0.2s; }
.stagger-reveal > *:nth-child(4) { animation-delay: 0.25s; }
.stagger-reveal > *:nth-child(5) { animation-delay: 0.3s; }
.stagger-reveal > *:nth-child(6) { animation-delay: 0.35s; }

/* Subtle hover glow */
@keyframes subtleGlow {
  0%, 100% { box-shadow: var(--shadow-soft); }
  50% { box-shadow: var(--shadow-soft), 0 0 20px rgba(184, 169, 201, 0.15); }
}

/* ============================================
   広告エリア
   ============================================ */
.ad-container {
  max-width: 100%;
  margin: 30px auto;
  padding: 20px;
  text-align: center;
  background: var(--gradient-main);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-medium);
  transition: transform var(--duration-normal) var(--ease-out-expo), box-shadow var(--duration-normal) var(--ease-out-expo);
  position: relative;
  overflow: hidden;
}

.ad-container::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.08) 0%, transparent 30%);
  pointer-events: none;
}

.ad-container:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-strong);
}

.ad-description {
  color: white;
  font-size: 0.9rem;
  margin-bottom: 1rem;
  opacity: 0.95;
  line-height: 1.6;
  position: relative;
  z-index: 1;
  font-family: var(--font-body);
  letter-spacing: 0.02em;
}

.ad-container > div {
  display: inline-block;
  background: var(--bg-card);
  padding: 15px;
  border-radius: var(--border-radius-sm);
  box-shadow: var(--shadow-soft);
  transition: transform var(--duration-normal) var(--ease-out-expo);
  position: relative;
  z-index: 1;
}

.ad-container:hover > div {
  transform: scale(1.02);
}

.ad-container a {
  word-wrap: break-word;
  display: block;
  text-decoration: none;
}

.ad-container img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  display: block;
  margin: 0 auto;
  transition: transform var(--duration-normal) var(--ease-out-expo);
}

.ad-container img:hover {
  transform: scale(1.05);
}

@media (max-width: 768px) {
  .ad-container {
    margin: 20px 10px;
    padding: 15px;
  }
}

/* ============================================
   プリントスタイル
   ============================================ */
@media print {
  .header, .footer, .share-section, .back-to-top, .toc, .ad-container {
    display: none;
  }

  .article-content {
    box-shadow: none;
    padding: 0;
  }

  .article-header {
    box-shadow: none;
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }
}