#snow-container {  
    height: 100%;
    overflow: hidden;
    position: absolute;
    top: 0;
    transition: opacity 500ms;
    width: 100%;
    z-index: -1;
}

body.boxed #snow-container {  
    z-index: 0;
}

.snow {
    animation: fall ease-in infinite, sway ease-in-out infinite;
    color: skyblue;
    border-color: white;
    position: absolute; 
}

@keyframes fall {
    0% {
      opacity: 0;
    }
    50% {
      opacity: 1;
    }
    100% {
      top: 100%;
      opacity: 1;
    }
  }
  
  @keyframes sway {
    0% {
      margin-left: 0;
    }
    25% {
      margin-left: 50px;
    }
    50% {
      margin-left: -50px;
    }
    75% {
      margin-left: 50px;
    }
    100% {
      margin-left: 0;
    }
  }