/* ============================================
   Animations - 严格遵循 ANIMATION_GUIDELINES.md
   ============================================ */

/* --- 入场动画 --- */
@keyframes fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slide-up {
  from { opacity: 0; transform: translateY(var(--translate-md)); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes slide-down {
  from { opacity: 0; transform: translateY(calc(-1 * var(--translate-md))); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes slide-left {
  from { opacity: 0; transform: translateX(var(--translate-md)); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes slide-right {
  from { opacity: 0; transform: translateX(calc(-1 * var(--translate-md))); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes zoom-in {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes blur-in {
  from { opacity: 0; filter: blur(8px); }
  to   { opacity: 1; filter: blur(0); }
}

/* --- 出场动画 --- */
@keyframes fade-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

@keyframes slide-away-down {
  from { opacity: 1; transform: translateY(0); }
  to   { opacity: 0; transform: translateY(var(--translate-md)); }
}

@keyframes slide-away-up {
  from { opacity: 1; transform: translateY(0); }
  to   { opacity: 0; transform: translateY(calc(-1 * var(--translate-md))); }
}

/* --- 循环动画 --- */
@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.6; }
}

/* --- 动画类 --- */
.animate-fade-in {
  animation: fade-in var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-slide-up {
  animation: slide-up var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-slide-down {
  animation: slide-down var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-slide-left {
  animation: slide-left var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-slide-right {
  animation: slide-right var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-zoom-in {
  animation: zoom-in var(--duration-slow) var(--ease-decelerate) forwards;
}

.animate-blur-in {
  animation: blur-in var(--duration-slow) var(--ease-decelerate) forwards;
}

/* --- 滚动触发 --- */
.reveal {
  opacity: 0;
  transform: translateY(var(--translate-md));
  transition: opacity var(--duration-slow) var(--ease-decelerate),
              transform var(--duration-slow) var(--ease-decelerate);
}

.reveal.in-view {
  opacity: 1;
  transform: translateY(0);
}

/* --- 无障碍降级 --- */
@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;
  }
}