*, *:before, *:after {
  box-sizing: border-box;
}

@-webkit-keyframes scrollBad {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 0 -320px;
  }
}
@keyframes scrollBad {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 0 -320px;
  }
}
@-webkit-keyframes scrollGood {
  0% {
    -webkit-transform: translate3d(0, 0, 0);
            transform: translate3d(0, 0, 0);
  }
  100% {
    -webkit-transform: translate3d(0, -320px, 0);
            transform: translate3d(0, -320px, 0);
  }
}
@keyframes scrollGood {
  0% {
    -webkit-transform: translate3d(0, 0, 0);
            transform: translate3d(0, 0, 0);
  }
  100% {
    -webkit-transform: translate3d(0, -320px, 0);
            transform: translate3d(0, -320px, 0);
  }
}

.bg {
  --background-color: #991932;
  background-image: url(../images/monster_background.png);
  background-image: url(../images/monster_background.svg);
  background-position: center center;
  background-size: 500px;
}

body.desktop.bg {
  -webkit-animation: scrollBad 10s linear infinite;
          animation: scrollBad 10s linear infinite;
}