body {
  background: radial-gradient(circle at 20% 20%, rgba(0, 255, 255, 0.1), transparent 40%),
    radial-gradient(circle at 80% 80%, rgba(255, 0, 255, 0.1), transparent 40%),
    #000;
  background-size: 200% 200%;
  animation: bgMove 35s ease infinite;
}

@keyframes bgMove {
  0% {
    background-position: 0% 0%;
  }

  50% {
    background-position: 100% 100%;
  }

  100% {
    background-position: 0% 0%;
  }
}