/* ==========================================================================
   Shared Animation Foundation
   Portfolio-wide animation tokens, reduced-motion handling, and UI classes.
   Import via <link rel="stylesheet" href="/shared/animations.css">
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS Custom Properties
   -------------------------------------------------------------------------- */

:root {
  --hover-lift: -2px;
  --hover-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  --focus-ring-color: var(--primary-color, #2196F3);
  --interaction-duration: 0.2s;
  --interaction-easing: cubic-bezier(0.22, 1, 0.36, 1);
  --entrance-duration: 0.6s;
  --skeleton-bg: #e0e0e0;
  --skeleton-shimmer: rgba(255, 255, 255, 0.4);
}

/* --------------------------------------------------------------------------
   2. Reduced-motion reset (ANIM-01 CSS layer)
   Uses 0.01ms (not "none") to prevent layout breaks from animations
   that set final position via forwards fill-mode.
   -------------------------------------------------------------------------- */

@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;
  }
}

/* --------------------------------------------------------------------------
   3. Interactive element hover/focus (ANIM-02 foundation)
   -------------------------------------------------------------------------- */

.interactive {
  transition: transform var(--interaction-duration) var(--interaction-easing),
              box-shadow var(--interaction-duration) var(--interaction-easing);
}

.interactive:hover {
  transform: translateY(var(--hover-lift));
  box-shadow: var(--hover-shadow);
}

.interactive:focus-visible {
  outline: 2px solid var(--focus-ring-color);
  outline-offset: 2px;
}

.interactive:active {
  transform: translateY(0);
  box-shadow: none;
}

/* --------------------------------------------------------------------------
   4. Skeleton shimmer (ANIM-03 foundation)
   -------------------------------------------------------------------------- */

@keyframes shimmer {
  0% {
    transform: translateX(-100%);
  }
  100% {
    transform: translateX(100%);
  }
}

.skeleton {
  background: var(--skeleton-bg);
  border-radius: 4px;
  position: relative;
  overflow: hidden;
}

.skeleton::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    var(--skeleton-shimmer),
    transparent
  );
  animation: shimmer 1.5s infinite;
}

/* Size variants */
.skeleton-text {
  height: 1em;
  margin-bottom: 0.5em;
}

.skeleton-text--short {
  width: 60%;
}

.skeleton-text--full {
  width: 100%;
}

.skeleton-circle {
  border-radius: 50%;
}

.skeleton-block {
  height: 120px;
  width: 100%;
}

/* State classes */
.is-loading .skeleton {
  visibility: visible;
}

.is-loaded {
  opacity: 1;
  transition: opacity 200ms ease;
}

/* --------------------------------------------------------------------------
   5. Form focus rings (MICRO-02 foundation)
   -------------------------------------------------------------------------- */

.animated-form input,
.animated-form textarea {
  border: 1px solid #ccc;
  transition: border-color var(--interaction-duration) var(--interaction-easing),
              box-shadow var(--interaction-duration) var(--interaction-easing);
}

.animated-form input:focus,
.animated-form textarea:focus {
  border-color: var(--focus-ring-color);
  box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.15);
  outline: none;
}

.validation-message {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height 0.3s var(--interaction-easing),
              opacity 0.2s var(--interaction-easing);
}

.validation-message.is-visible {
  max-height: 2em;
  opacity: 1;
}

/* --------------------------------------------------------------------------
   6. Nav link transitions (MICRO-03 foundation)
   -------------------------------------------------------------------------- */

.nav-link-animated {
  position: relative;
  transition: color var(--interaction-duration) var(--interaction-easing);
}

.nav-link-animated::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: currentColor;
  transition: width var(--interaction-duration) var(--interaction-easing);
}

.nav-link-animated:hover::after,
.nav-link-animated.active::after {
  width: 100%;
}