.snow-container {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  overflow: hidden;
  z-index: 9999;
}

.snowflake {
  position: absolute;
  top: -5%;
  animation-name: fallAndSpin;
  animation-timing-function: linear;
  animation-fill-mode: forwards;
}

@keyframes fallAndSpin {
  0%   { top: -5%; transform: translateX(0) rotate(0deg); opacity: 1; }
  50%  { top: 50%; transform: translateX(20px) rotate(180deg); opacity: 1; }
  100% { top: 95%; transform: translateX(-20px) rotate(360deg); opacity: 1; }
}