body {
  margin: 0;
  height: 100vh;
  background: linear-gradient(270deg,
    red, orange, yellow, green, cyan, blue, violet, red);
  background-size: 1600% 1600%;
  animation: rainbowMove 30s linear infinite;
}

@keyframes rainbowMove {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}
img {
      image-rendering: pixelated;
    }