/**
 * UN Decade KMS - Animation Utilities
 *
 * Performance-optimized animations using CSS transforms and opacity.
 * All animations respect prefers-reduced-motion.
 */

/* ============================================
   CSS Variables for Timing & Easing
   ============================================ */
:root {
  /* Durations */
  --duration-fast: 150ms;
  --duration-normal: 300ms;
  --duration-slow: 500ms;
  --duration-slower: 800ms;

  /* Easing functions */
  --ease-out: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-in-out: cubic-bezier(0.645, 0.045, 0.355, 1);
  --ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* ============================================
   Keyframe Animations
   ============================================ */

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

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

/* Slide */
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Scale */
@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes scaleOut {
  from {
    opacity: 1;
    transform: scale(1);
  }
  to {
    opacity: 0;
    transform: scale(0.9);
  }
}

/* Pulse */
@keyframes pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.8;
    transform: scale(1.05);
  }
}

@keyframes pulseSubtle {
  0%, 100% {
    box-shadow: 0 0 0 0 currentColor;
  }
  50% {
    box-shadow: 0 0 0 8px transparent;
  }
}

/* Shake (for errors/warnings) */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-4px); }
  20%, 40%, 60%, 80% { transform: translateX(4px); }
}

/* Bounce */
@keyframes bounceIn {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  50% {
    transform: scale(1.05);
  }
  70% {
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

/* Float (subtle hovering effect) */
@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* Gradient shift for backgrounds */
@keyframes gradientShift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

/* Text reveal (character by character effect) */
@keyframes textReveal {
  from {
    clip-path: inset(0 100% 0 0);
  }
  to {
    clip-path: inset(0 0 0 0);
  }
}

/* ============================================
   Animation Utility Classes
   ============================================ */

/* Fade animations */
.animate-fade-in {
  animation: fadeIn var(--duration-normal) var(--ease-out) forwards;
}

.animate-fade-out {
  animation: fadeOut var(--duration-normal) var(--ease-out) forwards;
}

/* Slide animations */
.animate-slide-up {
  animation: slideUp var(--duration-slow) var(--ease-out) forwards;
}

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

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

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

/* Scale animations */
.animate-scale-in {
  animation: scaleIn var(--duration-normal) var(--ease-spring) forwards;
}

.animate-scale-out {
  animation: scaleOut var(--duration-normal) var(--ease-out) forwards;
}

/* Bounce */
.animate-bounce-in {
  animation: bounceIn var(--duration-slow) var(--ease-out) forwards;
}

/* Pulse */
.animate-pulse {
  animation: pulse 2s var(--ease-in-out) infinite;
}

.animate-pulse-subtle {
  animation: pulseSubtle 2s var(--ease-in-out) infinite;
}

/* Shake */
.animate-shake {
  animation: shake 0.5s var(--ease-out);
}

/* Float */
.animate-float {
  animation: float 3s var(--ease-in-out) infinite;
}

/* ============================================
   Stagger Delay Classes
   ============================================ */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }
.stagger-5 { animation-delay: 0.5s; }
.stagger-6 { animation-delay: 0.6s; }
.stagger-7 { animation-delay: 0.7s; }
.stagger-8 { animation-delay: 0.8s; }

/* ============================================
   Scroll-Triggered Animations
   ============================================ */

/* Base scroll reveal - elements start hidden */
.scroll-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

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

/* Variants */
.scroll-reveal-left {
  opacity: 0;
  transform: translateX(-30px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

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

.scroll-reveal-right {
  opacity: 0;
  transform: translateX(30px);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

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

.scroll-reveal-scale {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-spring);
}

.scroll-reveal-scale.is-visible {
  opacity: 1;
  transform: scale(1);
}

/* Staggered children */
.scroll-reveal-stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--duration-normal) var(--ease-out),
              transform var(--duration-normal) var(--ease-out);
}

.scroll-reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0s; opacity: 1; transform: translateY(0); }
.scroll-reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 0.1s; opacity: 1; transform: translateY(0); }
.scroll-reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 0.2s; opacity: 1; transform: translateY(0); }
.scroll-reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 0.3s; opacity: 1; transform: translateY(0); }
.scroll-reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 0.4s; opacity: 1; transform: translateY(0); }
.scroll-reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 0.5s; opacity: 1; transform: translateY(0); }

/* ============================================
   Hero Section Animations
   ============================================ */

/* Fullscreen hero sizing (account for sticky nav height) */
.hero-fullscreen {
  min-height: calc(100vh - 4rem);
  min-height: calc(100svh - 4rem);
  display: flex;
  align-items: center;
}

/* Hero text lines - staggered reveal */
.hero-text-reveal {
  opacity: 0;
  transform: translateY(20px);
  animation: slideUp var(--duration-slower) var(--ease-out) forwards;
}

.hero-text-reveal:nth-child(1) { animation-delay: 0.2s; }
.hero-text-reveal:nth-child(2) { animation-delay: 0.4s; }
.hero-text-reveal:nth-child(3) { animation-delay: 0.6s; }

/* Hero CTA buttons */
.hero-cta-reveal {
  opacity: 0;
  transform: translateY(20px);
  animation: slideUp var(--duration-slow) var(--ease-out) forwards;
  animation-delay: 0.8s;
}

/* Hero search card */
.hero-card-reveal {
  opacity: 0;
  transform: translateX(40px);
  animation: slideInRight var(--duration-slower) var(--ease-out) forwards;
  animation-delay: 0.5s;
}

/* Parallax helper */
.parallax-bg {
  transform: translateZ(0);
  will-change: transform;
}

/* ============================================
   Interactive Element Animations
   ============================================ */

/* Enhanced card hover */
.card-hover-lift {
  transition: transform var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
}

.card-hover-lift:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

/* Button press effect */
.btn-press {
  transition: transform var(--duration-fast) var(--ease-out);
}

.btn-press:active {
  transform: scale(0.95);
}

/* Link underline animation */
.link-underline {
  position: relative;
}

.link-underline::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: currentColor;
  transition: width var(--duration-normal) var(--ease-out);
}

.link-underline:hover::after {
  width: 100%;
}

/* ============================================
   Loading Animations
   ============================================ */

/* Skeleton loading shimmer */
@keyframes shimmer {
  0% {
    background-position: -200% 0;
  }
  100% {
    background-position: 200% 0;
  }
}

.skeleton-loading {
  background: linear-gradient(
    90deg,
    rgba(200, 200, 200, 0.2) 25%,
    rgba(200, 200, 200, 0.4) 50%,
    rgba(200, 200, 200, 0.2) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

html.dark .skeleton-loading {
  background: linear-gradient(
    90deg,
    rgba(100, 100, 100, 0.2) 25%,
    rgba(100, 100, 100, 0.4) 50%,
    rgba(100, 100, 100, 0.2) 75%
  );
  background-size: 200% 100%;
}

/* Spinner */
@keyframes spin {
  to { transform: rotate(360deg); }
}

.animate-spin {
  animation: spin 1s linear infinite;
}

/* ============================================
   Reduced Motion Support
   ============================================ */
@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;
  }

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

  .scroll-reveal-stagger > * {
    opacity: 1;
    transform: none;
  }

  .hero-text-reveal,
  .hero-cta-reveal,
  .hero-card-reveal {
    opacity: 1;
    transform: none;
    animation: none;
  }

  .animate-pulse,
  .animate-pulse-subtle,
  .animate-float {
    animation: none;
  }
}