/* ============================================================
   animations.css — 4 级动效系统
   页面入场 / 滚动揭示 / hover 反馈 / 微交互
   所有动画包裹 @media (prefers-reduced-motion: reduce)
   ============================================================ */

/* ============================================================
   A. 页面入场 (Stagger Fade-In-Up)
   每个子元素延迟递增 50ms
   ============================================================ */

/* 基础入场单元 */
.pv-fade-in-up {
  opacity: 0;
  transform: translateY(20px);
  animation: pv-fade-in-up var(--pv-duration-slow) var(--pv-ease) forwards;
}

@keyframes pv-fade-in-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Stagger 延迟工具类 */
.pv-stagger > *:nth-child(1)  { animation-delay: 0ms; }
.pv-stagger > *:nth-child(2)  { animation-delay: 50ms; }
.pv-stagger > *:nth-child(3)  { animation-delay: 100ms; }
.pv-stagger > *:nth-child(4)  { animation-delay: 150ms; }
.pv-stagger > *:nth-child(5)  { animation-delay: 200ms; }
.pv-stagger > *:nth-child(6)  { animation-delay: 250ms; }
.pv-stagger > *:nth-child(7)  { animation-delay: 300ms; }
.pv-stagger > *:nth-child(8)  { animation-delay: 350ms; }
.pv-stagger > *:nth-child(9)  { animation-delay: 400ms; }
.pv-stagger > *:nth-child(10) { animation-delay: 450ms; }
.pv-stagger > *:nth-child(11) { animation-delay: 500ms; }
.pv-stagger > *:nth-child(12) { animation-delay: 550ms; }
.pv-stagger > *:nth-child(13) { animation-delay: 600ms; }
.pv-stagger > *:nth-child(14) { animation-delay: 650ms; }
.pv-stagger > *:nth-child(15) { animation-delay: 700ms; }
.pv-stagger > *:nth-child(16) { animation-delay: 750ms; }
.pv-stagger > *:nth-child(17) { animation-delay: 800ms; }
.pv-stagger > *:nth-child(18) { animation-delay: 850ms; }
.pv-stagger > *:nth-child(19) { animation-delay: 900ms; }
.pv-stagger > *:nth-child(20) { animation-delay: 950ms; }

/* 确保 stagger 子元素初始状态透明 */
.pv-stagger > * {
  opacity: 0;
  animation: pv-fade-in-up var(--pv-duration-slow) var(--pv-ease) forwards;
}

/* ============================================================
   B. 滚动揭示 (配合 Intersection Observer)
   需要 JS 添加 .pv-reveal--visible 类名
   ============================================================ */

.pv-reveal {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--pv-duration-slow) var(--pv-ease),
    transform var(--pv-duration-slow) var(--pv-ease);
}

.pv-reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* 不同方向的滚动揭示 */
.pv-reveal--left {
  transform: translateX(-24px);
}

.pv-reveal--left.pv-reveal--visible {
  transform: translateX(0);
}

.pv-reveal--right {
  transform: translateX(24px);
}

.pv-reveal--right.pv-reveal--visible {
  transform: translateX(0);
}

.pv-reveal--scale {
  transform: scale(0.92);
}

.pv-reveal--scale.pv-reveal--visible {
  transform: scale(1);
}

/* ============================================================
   C. hover 反馈动画
   ============================================================ */

/* 通用 hover 提升 */
.pv-hover-lift {
  transition: transform var(--pv-duration-fast) var(--pv-ease);
}

.pv-hover-lift:hover {
  transform: translateY(-2px);
}

/* ============================================================
   已废弃的动画（暗色 glow 不再适用）
   .pv-hover-glow, .pv-breathe 保留类名但移除发光效果
   ============================================================ */

/* hover 发光 → 改为阴影（保留兼容） */
.pv-hover-glow {
  transition: box-shadow var(--pv-duration-normal) var(--pv-ease);
}

.pv-hover-glow:hover {
  box-shadow: var(--pv-shadow-card-hover);
}

/* 呼吸 → 无效果（保留兼容） */
.pv-breathe {
  /* no-op：亮色风格不使用呼吸发光 */
}
.pv-hover-scale {
  transition: transform var(--pv-duration-fast) var(--pv-ease);
}

.pv-hover-scale:hover {
  transform: scale(1.04);
}

/* ============================================================
   D. 微交互
   ============================================================ */

/* 脉冲 (吸引注意) */
.pv-pulse {
  animation: pv-pulse 2s var(--pv-ease) infinite;
}

@keyframes pv-pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.5; }
}

/* 摇晃 (错误提示) */
.pv-shake {
  animation: pv-shake 0.4s var(--pv-ease);
}

@keyframes pv-shake {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-6px); }
  40%      { transform: translateX(6px); }
  60%      { transform: translateX(-4px); }
  80%      { transform: translateX(4px); }
}

/* 旋转 (加载指示) */
.pv-spin {
  animation: pv-spin 0.8s linear infinite;
}

@keyframes pv-spin {
  to { transform: rotate(360deg); }
}

/* 淡入 */
.pv-fade-in {
  animation: pv-fade-in var(--pv-duration-normal) var(--pv-ease);
}

@keyframes pv-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* 滑入上 */
.pv-slide-up {
  animation: pv-slide-up var(--pv-duration-normal) var(--pv-ease-spring);
}

@keyframes pv-slide-up {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   E. prefers-reduced-motion — 尊重用户运动偏好
   所有动画在此禁用或最小化
   ============================================================ */

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

  html {
    scroll-behavior: auto;
  }

  .pv-fade-in-up,
  .pv-stagger > * {
    opacity: 1;
    transform: none;
    animation: none;
  }

  .pv-reveal,
  .pv-reveal--left,
  .pv-reveal--right,
  .pv-reveal--scale {
    opacity: 1;
    transform: none;
    transition: none;
  }
}