body {
  background-image:
    radial-gradient(at 0 0, #ff9 60%, transparent 90%),
    radial-gradient(at 110% 20%, #f80 20%, transparent 30%),
    radial-gradient(at 110% 60%, #f08 10%, transparent 40%),
    radial-gradient(at 100% 100%, #bd29d0, transparent);
  background-attachment: fixed;
}