/* ============================================================
   KEYFRAMES
   ============================================================ */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(32px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-32px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(32px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

@keyframes glowPulse {
  0%, 100% {
    box-shadow: 0 0 10px rgba(201, 162, 39, 0.20),
                0 0 20px rgba(201, 162, 39, 0.10);
  }
  50% {
    box-shadow: 0 0 24px rgba(201, 162, 39, 0.50),
                0 0 48px rgba(201, 162, 39, 0.25);
  }
}

@keyframes glowPulseText {
  0%, 100% { text-shadow: 0 0 8px rgba(201, 162, 39, 0.30); }
  50%       { text-shadow: 0 0 20px rgba(201, 162, 39, 0.70); }
}

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

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

@keyframes flicker {
  0%,  19%,  21%,  23%,  25%,  54%,  56%, 100% { opacity: 1; }
  20%, 22%,  24%,  55% { opacity: 0.4; }
}

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

@keyframes borderGlow {
  0%, 100% { border-color: rgba(201, 162, 39, 0.25); }
  50%       { border-color: rgba(201, 162, 39, 0.65); }
}

@keyframes riseAndFade {
  0%   { opacity: 0; transform: translateY(8px); }
  20%  { opacity: 1; transform: translateY(0); }
  80%  { opacity: 1; transform: translateY(0); }
  100% { opacity: 0; transform: translateY(-8px); }
}

/* ============================================================
   SCROLL-TRIGGERED ANIMATION BASE
   Elements start invisible; JS adds .is-visible to trigger
   ============================================================ */

.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity  var(--transition-slow),
    transform var(--transition-slow);
}

.animate-on-scroll.from-left {
  transform: translateX(-24px);
}

.animate-on-scroll.from-right {
  transform: translateX(24px);
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translate(0);
}

/* Staggered children */
.animate-on-scroll.delay-1 { transition-delay: 100ms; }
.animate-on-scroll.delay-2 { transition-delay: 200ms; }
.animate-on-scroll.delay-3 { transition-delay: 300ms; }
.animate-on-scroll.delay-4 { transition-delay: 400ms; }
.animate-on-scroll.delay-5 { transition-delay: 500ms; }
.animate-on-scroll.delay-6 { transition-delay: 600ms; }

/* ============================================================
   UTILITY ANIMATION CLASSES
   ============================================================ */

.glow {
  animation: glowPulse 3s ease-in-out infinite;
}

.glow-text {
  animation: glowPulseText 3s ease-in-out infinite;
}

.rotate-slow {
  animation: slowRotate 40s linear infinite;
}

.rotate-slow-ccw {
  animation: slowRotateCCW 40s linear infinite;
}

.flicker {
  animation: flicker 4s linear infinite;
}

.fade-in {
  animation: fadeIn 1s ease both;
}

.fade-in-up {
  animation: fadeInUp 0.8s ease both;
}

/* ============================================================
   GRAIN / NOISE TEXTURE OVERLAY
   Apply to a pseudo-element or a dedicated <div class="grain-overlay">
   ============================================================ */

.grain-overlay {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: var(--z-overlay);
  opacity: 0.035;
  filter: url(#grain);
}

/* The SVG filter for grain is injected by JS into a hidden <svg> in the DOM.
   Fallback: CSS-only noise via repeating-conic-gradient approximation. */
.grain-overlay::after {
  content: '';
  position: absolute;
  inset: -50%;
  width: 200%; height: 200%;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='1'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 128px 128px;
}

/* ============================================================
   PAGE TRANSITION
   ============================================================ */

.page-transition-out {
  animation: fadeIn 0.3s ease reverse both;
}

.page-transition-in {
  animation: fadeIn 0.3s ease both;
}

/* ============================================================
   SHIMMER / GOLD SHEEN (for headings and special elements)
   ============================================================ */

.shimmer-gold {
  background: linear-gradient(
    90deg,
    var(--color-sulphur-gold) 0%,
    var(--color-sulphur-light) 40%,
    var(--color-vellum-cream) 50%,
    var(--color-sulphur-light) 60%,
    var(--color-sulphur-gold) 100%
  );
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: shimmer 4s linear infinite;
}

/* ============================================================
   REDUCED MOTION
   ============================================================ */

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

  .animate-on-scroll {
    opacity: 1;
    transform: none;
  }

  .grain-overlay {
    display: none;
  }
}