/* ============================================================
   Keyframes
   ============================================================ */

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

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

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

@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

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

/* ============================================================
   Scroll-reveal system
   ============================================================ */

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}

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

/* Stagger siblings */
.reveal:nth-child(2) { transition-delay: 80ms; }
.reveal:nth-child(3) { transition-delay: 160ms; }
.reveal:nth-child(4) { transition-delay: 240ms; }
.reveal:nth-child(5) { transition-delay: 320ms; }

/* ============================================================
   Skeleton loading
   ============================================================ */

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-surface) 25%,
    var(--color-surface-raised) 50%,
    var(--color-surface) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

/* ============================================================
   Spinner
   ============================================================ */

.spinner {
  width: 20px;
  height: 20px;
  border: 2px solid rgba(var(--color-primary-rgb), 0.3);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
}

/* ============================================================
   Reduced-motion overrides
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .reveal.visible {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .skeleton {
    animation: none;
    background: var(--color-surface-raised);
  }

  .spinner {
    animation: none;
  }
}