Animating Background Gradient

#box {
  background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
  background-size: 120% 120%;
  animation: gradient 15s ease infinite;    
}

/* Define keyframes for gradient animation */
@keyframes gradient {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}