/* ============================================================
   ABOUT HISTORY — 沿革タイムライン
   背景: white (#FFFFFF)
   レイアウト: 縦タイムライン（中央線 + 左右交互配置）
   モバイル: 左寄せ1カラム
   ============================================================ */

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

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

/* ---- Section Header ---- */
.about-history__header {
  text-align: center;
  margin-bottom: 72px;
}

.about-history__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-orange, #E8672A);
  margin: 0 0 12px;
}

.about-history__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: 1.5;
}

.about-history__line {
  width: 48px;
  height: 3px;
  background: var(--c-orange, #E8672A);
  border-radius: 2px;
  margin: 0 auto;
}

/* ---- Timeline Container ---- */
.about-history__timeline {
  position: relative;
  max-width: 860px;
  margin: 0 auto;
}

/* 中央縦線 */
.about-history__timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--c-border, #E5E5E5);
  transform: translateX(-50%);
  border-radius: 1px;
}

/* ---- Timeline Item ---- */
.about-history__item {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 48px 1fr;
  gap: 0;
  align-items: center;
  margin-bottom: 48px;
}

.about-history__item:last-child {
  margin-bottom: 0;
}

/* ---- Dot (中央ライン上の●) ---- */
.about-history__dot-wrap {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  z-index: 1;
  /* 最小高さをカードに合わせる */
  align-self: stretch;
  padding: 24px 0;
}

.about-history__dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--c-orange, #E8672A);
  border: 3px solid var(--c-bg, #FFFFFF);
  box-shadow: 0 0 0 2px var(--c-orange, #E8672A);
  flex-shrink: 0;
  align-self: flex-start;
  margin-top: 20px;
  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));
}

.about-history__item:hover .about-history__dot {
  transform: scale(1.35);
  box-shadow: 0 0 0 3px var(--c-orange, #E8672A), 0 0 0 6px rgba(232, 103, 42, 0.15);
}

/* ---- Void (空スペーサー) ---- */
.about-history__void {
  /* 空要素: グリッドのバランス用 */
}

/* ---- Card ---- */
.about-history__card {
  background: var(--c-bg, #FFFFFF);
  border: 1px solid var(--c-border-light, #F0F0F0);
  border-radius: 10px;
  padding: 22px 26px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
  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));
}

.about-history__item:hover .about-history__card {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.09);
}

/* 左アイテム（デフォルト）: カード右端にオレンジボーダー */
.about-history__item:not(.about-history__item--alt) .about-history__card {
  margin-right: 16px;
  border-right: 3px solid var(--c-orange, #E8672A);
  border-left: 1px solid var(--c-border-light, #F0F0F0);
}

/* 右アイテム（--alt）: カード左端にオレンジボーダー */
.about-history__item--alt .about-history__card {
  margin-left: 16px;
  border-left: 3px solid var(--c-orange, #E8672A);
  border-right: 1px solid var(--c-border-light, #F0F0F0);
}

/* 日付 */
.about-history__date {
  display: block;
  font-family: var(--f-label, 'Inter', sans-serif);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--c-orange, #E8672A);
  margin-bottom: 8px;
  text-transform: uppercase;
}

/* 説明文 */
.about-history__desc {
  font-family: var(--f-body, 'Noto Sans JP', sans-serif);
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--c-text, #1A1A1A);
  line-height: 1.85;
  margin: 0;
  letter-spacing: 0.02em;
}

/* .rv / .rv.is-visible / .rv.d1〜d6 は base.css に集約済み */

/* ---- Responsive: Tablet (1024px) ---- */
@media (max-width: 1024px) {
  .about-history__timeline {
    max-width: 720px;
  }
}

/* ---- Responsive: Tablet/Mobile (768px) — 左寄せ1カラム ---- */
@media (max-width: 768px) {
  .about-history {
    padding: 72px 20px;
  }

  .about-history__header {
    margin-bottom: 48px;
  }

  /* 縦線を左端に移動 */
  .about-history__timeline::before {
    left: 20px;
    transform: none;
  }

  /* アイテムをブロック表示・左パディング確保 */
  .about-history__item,
  .about-history__item--alt {
    display: block;
    position: relative;
    padding-left: 56px;
    margin-bottom: 32px;
  }

  /* 空スペーサー非表示 */
  .about-history__void {
    display: none;
  }

  /* ドットを縦線上に絶対配置 */
  .about-history__dot-wrap {
    position: absolute;
    left: 12px; /* 縦線中心20px - ドット半径8px = 12px */
    top: 22px;
    padding: 0;
    display: block;
    align-self: auto;
  }

  .about-history__dot {
    margin-top: 0;
    width: 16px;
    height: 16px;
  }

  /* カードのマージン・ボーダーをモバイル用に統一 */
  .about-history__item:not(.about-history__item--alt) .about-history__card,
  .about-history__item--alt .about-history__card {
    margin: 0;
    border-left: 3px solid var(--c-orange, #E8672A);
    border-right: 1px solid var(--c-border-light, #F0F0F0);
    border-top: 1px solid var(--c-border-light, #F0F0F0);
    border-bottom: 1px solid var(--c-border-light, #F0F0F0);
  }
}

/* ---- Responsive: Mobile (480px) ---- */
@media (max-width: 480px) {
  .about-history {
    padding: 56px 16px;
  }

  .about-history__card {
    padding: 18px 20px;
  }

  .about-history__desc {
    font-size: 0.85rem;
  }

  .about-history__date {
    font-size: 0.73rem;
  }
}