/* Ensure header contains the snow */
header {
  position: relative;
  overflow: hidden;
}

/* Snow layers */
.snow,
.snow::before,
.snow::after {
  position: absolute;
  inset: -200% 0; /* extra tall so flakes are always flowing */
  content: "";
  pointer-events: none;
  z-index: 20;
  background-repeat: repeat;
  background-size: 220px 220px;
  animation: snow-fall 40s linear infinite;
}

/* Back layer: small flakes */
.snow {
  background-image:
    radial-gradient(2px 2px at 20px 30px, var(--snow) 50%, transparent 60%),
    radial-gradient(2px 2px at 120px 90px, var(--snow) 50%, transparent 60%),
    radial-gradient(2px 2px at 180px 160px, var(--snow) 50%, transparent 60%);
  opacity: 0.6;
}

/* Mid layer: mixed medium flakes */
.snow::before {
  background-image:
    radial-gradient(3px 3px at 40px 60px, var(--snow) 50%, transparent 60%),
    radial-gradient(2.5px 2.5px at 160px 140px, var(--snow) 50%, transparent 60%);
  opacity: 0.8;
}

/* Front layer: large flakes */
.snow::after {
  background-image:
    radial-gradient(4px 4px at 60px 40px, var(--snow) 50%, transparent 60%),
    radial-gradient(4px 4px at 200px 180px, var(--snow) 50%, transparent 60%);
  opacity: 1;
}

/* Slow, deep fall to hide the loop */
@keyframes snow-fall {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(220px);
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  .snow,
  .snow::before,
  .snow::after {
    animation: none;
  }
}

/* Accessibility: respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  .snow,
  .snow::before,
  .snow::after {
    animation: none;
  }
}