/**
 * animations.css — アニメーション定義
 * prefers-reduced-motion を必ず考慮する（CLAUDE.md コーディング規約）
 */

/* ============================================================
   @keyframes 定義
   ============================================================ */

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.92);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

/* ヒーローオーバーレイ用 */
@keyframes heroFadeIn {
  from { opacity: 0; transform: scale(1.04); }
  to   { opacity: 1; transform: scale(1); }
}

/* 区切り線ドロー */
@keyframes lineGrow {
  from { width: 0; }
  to   { width: 100%; }
}

/* ============================================================
   Intersection Observer 連動クラス
   JS から .is-visible を付与してアニメーション発火
   ============================================================ */

.anim-fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.anim-fade-up.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.anim-fade-left {
  opacity: 0;
  transform: translateX(-24px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.anim-fade-left.is-visible {
  opacity: 1;
  transform: translateX(0);
}

.anim-fade-right {
  opacity: 0;
  transform: translateX(24px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.anim-fade-right.is-visible {
  opacity: 1;
  transform: translateX(0);
}

.anim-scale-in {
  opacity: 0;
  transform: scale(0.92);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.anim-scale-in.is-visible {
  opacity: 1;
  transform: scale(1);
}

/* ステガード遅延（複数要素を順番にフェイン） */
.anim-stagger > * {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

.anim-stagger.is-visible > *:nth-child(1) { transition-delay:   0ms; }
.anim-stagger.is-visible > *:nth-child(2) { transition-delay:  50ms; }
.anim-stagger.is-visible > *:nth-child(3) { transition-delay: 100ms; }
.anim-stagger.is-visible > *:nth-child(4) { transition-delay: 150ms; }
.anim-stagger.is-visible > *:nth-child(5) { transition-delay: 200ms; }
.anim-stagger.is-visible > *:nth-child(6) { transition-delay: 250ms; }

.anim-stagger.is-visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   prefers-reduced-motion：アニメーション無効化
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .anim-fade-up,
  .anim-fade-left,
  .anim-fade-right,
  .anim-scale-in {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .anim-stagger > * {
    opacity: 1;
    transform: none;
    transition: none;
  }
}