/* ========================================
   FILM GRAIN OVERLAY
======================================== */
.grain {
  position: fixed;
  inset: 0;
  z-index: 99999;
  pointer-events: none;
  overflow: hidden;
  isolation: isolate;
}

.grain::before,
.grain::after {
  content: '';
  position: absolute;
  top: -150%;
  left: -150%;
  width: 400%;
  height: 400%;
  background-repeat: repeat;
  will-change: transform;
}

.grain::before {
  opacity: 0.015;
  mix-blend-mode: soft-light;
  background-size: 180px 180px;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  animation: grain-fine 0.45s steps(8) infinite;
}

.grain::after {
  opacity: 0.045;
  mix-blend-mode: soft-light;
  background-size: 350px 350px;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.45' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  animation: grain-coarse 1.2s steps(6) infinite reverse;
}

@keyframes grain-fine {
  0% {
    transform: translate3d(0, 0, 0);
  }
  12.5% {
    transform: translate3d(-3%, -4%, 0);
  }
  25% {
    transform: translate3d(2%, 3%, 0);
  }
  37.5% {
    transform: translate3d(-4%, 2%, 0);
  }
  50% {
    transform: translate3d(3%, -3%, 0);
  }
  62.5% {
    transform: translate3d(-2%, 4%, 0);
  }
  75% {
    transform: translate3d(4%, -2%, 0);
  }
  87.5% {
    transform: translate3d(-3%, 1%, 0);
  }
  100% {
    transform: translate3d(0, 0, 0);
  }
}

@keyframes grain-coarse {
  0% {
    transform: translate3d(0, 0, 0);
  }
  16.67% {
    transform: translate3d(5%, -3%, 0);
  }
  33.33% {
    transform: translate3d(-4%, 5%, 0);
  }
  50% {
    transform: translate3d(3%, 2%, 0);
  }
  66.67% {
    transform: translate3d(-5%, -4%, 0);
  }
  83.33% {
    transform: translate3d(2%, 3%, 0);
  }
  100% {
    transform: translate3d(0, 0, 0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .grain::before,
  .grain::after {
    animation: none;
  }
}