/* ============================================================
   KOSEN STORY — 代表タイムライン
   背景: white (#FFFFFF)
   レイアウト: 縦タイムライン（左寄せ1カラム・5ノード）
   アクセント: ゴールド（var(--c-gold)）
   アニメーション: rvシステム（rv-left / rv-up + d1〜d5）
   z-index: var(--z-content, 10) 必須
   ============================================================ */

/* ---- Section Base ---- */
.kosen-story {
  position: relative;
  z-index: var(--z-content, 10);
  background: var(--c-bg, #FFFFFF);
  padding: 96px var(--s-gutter, 32px);
  overflow: hidden;
}

/* ---- Container ---- */
.kosen-story__container {
  max-width: var(--s-container, 1200px);
  margin: 0 auto;
}

/* ============================================================
   Section Header
   ============================================================ */
.kosen-story__header {
  text-align: center;
  margin-bottom: 72px;
}

.kosen-story__eyebrow {
  font-family: var(--f-label, 'Inter', sans-serif);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-gold);
  margin: 0 0 12px;
}

.kosen-story__title {
  font-family: var(--f-heading-ja, 'Noto Serif JP', serif);
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  font-weight: 700;
  color: var(--c-text, #1A1A1A);
  margin: 0 0 16px;
  letter-spacing: 0.04em;
  line-height: 1.6;
}

.kosen-story__accent-line {
  width: 48px;
  height: 3px;
  background: var(--c-gold);
  border-radius: 2px;
  margin: 0 auto;
}

/* ============================================================
   Timeline
   ============================================================ */
.kosen-story__timeline {
  position: relative;
  max-width: 720px;
  margin: 0 auto;
  padding-left: 48px;
}

/* 縦ライン（左寄せ） */
.kosen-story__timeline::before {
  content: '';
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(
    180deg,
    var(--c-gold) 0%,
    var(--c-border, #E5E5E5) 30%,
    var(--c-border, #E5E5E5) 70%,
    var(--c-gold) 100%
  );
  border-radius: 1px;
}

/* ---- Timeline Item ---- */
.kosen-story__item {
  position: relative;
  display: flex;
  align-items: flex-start;
  margin-bottom: 40px;
}

.kosen-story__item:last-child {
  margin-bottom: 0;
}

/* ---- Dot (タイムラインノード) ---- */
.kosen-story__dot-wrap {
  position: absolute;
  left: -48px;
  top: 24px;
  width: 32px;
  display: flex;
  justify-content: center;
}

.kosen-story__dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-gold);
  border: 3px solid var(--c-bg, #FFFFFF);
  box-shadow: 0 0 0 2px var(--c-gold);
  flex-shrink: 0;
  transition: transform 0.3s var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1)),
              box-shadow 0.3s var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1));
}

.kosen-story__item:hover .kosen-story__dot {
  transform: scale(1.35);
  box-shadow: 0 0 0 3px var(--c-gold), 0 0 0 6px rgba(201, 168, 76, 0.2);
}

/* ハイライトノード（設立・現在）— ゴールド大きめ */
.kosen-story__item--highlight .kosen-story__dot {
  width: 18px;
  height: 18px;
  background: var(--c-gold);
  box-shadow: 0 0 0 2px var(--c-gold), 0 0 0 5px rgba(201, 168, 76, 0.15);
}

.kosen-story__item--highlight:hover .kosen-story__dot {
  box-shadow: 0 0 0 3px var(--c-gold), 0 0 0 8px rgba(201, 168, 76, 0.25);
}

/* ---- Card ---- */
.kosen-story__card {
  flex: 1;
  background: var(--c-bg, #FFFFFF);
  border: 1px solid var(--c-border-light, #F0F0F0);
  border-left: 3px solid var(--c-gold);
  border-radius: 10px;
  padding: 24px 28px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  transition: transform 0.3s var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1)),
              box-shadow 0.3s var(--ease-out, cubic-bezier(0.16, 1, 0.3, 1));
}

.kosen-story__item:hover .kosen-story__card {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
}

/* ハイライトカード — ゴールド背景グラデーション */
.kosen-story__item--highlight .kosen-story__card {
  background: linear-gradient(135deg, #FFFDF5 0%, #FFFFFF 100%);
  border-left: 4px solid var(--c-gold);
  box-shadow: 0 4px 16px rgba(201, 168, 76, 0.1);
}

.kosen-story__item--highlight:hover .kosen-story__card {
  box-shadow: 0 8px 32px rgba(201, 168, 76, 0.18);
}

/* 年号 */
.kosen-story__year {
  display: inline-block;
  font-family: var(--f-label, 'Inter', sans-serif);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--c-gold);
  background: rgba(201, 168, 76, 0.08);
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 10px;
}

/* カードタイトル */
.kosen-story__card-title {
  font-family: var(--f-heading-ja, 'Noto Sans JP', sans-serif);
  font-size: 1rem;
  font-weight: 700;
  color: var(--c-text, #1A1A1A);
  margin: 0 0 8px;
  line-height: 1.6;
  letter-spacing: 0.02em;
}

/* カード説明文 */
.kosen-story__card-desc {
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: 0.88rem;
  font-weight: 400;
  color: var(--c-text-light, #555555);
  line-height: 1.85;
  margin: 0;
  letter-spacing: 0.02em;
}

/* .rv / .rv.is-visible / .rv.d1〜d5 は base.css に集約済み */

/* ============================================================
   Closing Quote
   ============================================================ */
.kosen-story__closing {
  margin-top: 64px;
  text-align: center;
}

.kosen-story__quote {
  position: relative;
  display: inline-block;
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 40px;
  background: linear-gradient(135deg, rgba(201, 168, 76, 0.04) 0%, rgba(201, 168, 76, 0.01) 100%);
  border-radius: 12px;
  border: 1px solid rgba(201, 168, 76, 0.15);
}

/* 装飾クォーテーションマーク */
.kosen-story__quote::before {
  content: '\201C'; /* " */
  position: absolute;
  top: -12px;
  left: 24px;
  font-family: 'Georgia', serif;
  font-size: 4rem;
  line-height: 1;
  color: var(--c-gold);
  opacity: 0.3;
}

.kosen-story__quote p {
  font-family: var(--f-heading-ja, 'Noto Serif JP', serif);
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  font-weight: 600;
  color: var(--c-text, #1A1A1A);
  line-height: 2;
  margin: 0;
  letter-spacing: 0.04em;
}

/* ============================================================
   Responsive: Tablet (1024px)
   ============================================================ */
@media (max-width: 1024px) {
  .kosen-story__timeline {
    max-width: 600px;
  }
}

/* ============================================================
   Responsive: Mobile (768px)
   ============================================================ */
@media (max-width: 768px) {
  .kosen-story {
    padding: 72px 20px;
  }

  .kosen-story__header {
    margin-bottom: 48px;
  }

  .kosen-story__timeline {
    padding-left: 40px;
  }

  .kosen-story__timeline::before {
    left: 11px;
  }

  .kosen-story__dot-wrap {
    left: -40px;
    width: 24px;
  }

  .kosen-story__dot {
    width: 12px;
    height: 12px;
  }

  .kosen-story__item--highlight .kosen-story__dot {
    width: 15px;
    height: 15px;
  }

  .kosen-story__card {
    padding: 20px 22px;
  }

  .kosen-story__item {
    margin-bottom: 28px;
  }

  .kosen-story__closing {
    margin-top: 48px;
  }

  .kosen-story__quote {
    padding: 24px 24px;
  }

  .kosen-story__quote::before {
    font-size: 3rem;
    top: -8px;
    left: 16px;
  }
}

/* ============================================================
   Responsive: Small Mobile (480px)
   ============================================================ */
@media (max-width: 480px) {
  .kosen-story {
    padding: 56px 16px;
  }

  .kosen-story__card {
    padding: 18px 18px;
  }

  .kosen-story__card-title {
    font-size: 0.93rem;
  }

  .kosen-story__card-desc {
    font-size: 0.83rem;
  }

  .kosen-story__quote p {
    font-size: 0.95rem;
  }
}