html {
  height:100%;
}

body {
  margin:0;
}

.bg {
  animation:slide 40s ease-in-out infinite alternate;
  background-image: linear-gradient(-60deg, rgb(214, 214, 214) 50%, rgb(255, 255, 255) 50%);
  bottom:0;
  left:-50%;
  opacity:.5;
  position:fixed;
  right:-50%;
  top:0;
  z-index:-1;
}

.bg2 {
  animation-direction:alternate-reverse;
  animation-duration:50s;
}

.bg3 {
  animation-duration:70s;
}

.content {
  left:50%;
  padding:10vmin;
  position:fixed;
  text-align:center;
  top:50%;
  transform:translate(-50%, -50%);
}

h1 {
  font-family:monospace;
}

@keyframes slide {
  0% {
    transform:translateX(-25%);
  }
  100% {
    transform:translateX(25%);
  }
}