body {
  background-color: #3c53ff;
  margin-top: 0px;
  margin-left: 10px;
  margin-right: 10px;
  margin-bottom: 10px;
  font-family: arial, sans-serif;
  -webkit-animation-name: shc; /* Chrome, Safari, Opera */
  -webkit-animation-duration: 20; /* Chrome, Safari, Opera */
  -webkit-animation-iteration-count: infinite; /* Chrome, Safari, Opera */
  animation-name: shc;
  animation-duration: 20;
  animation-iteration-count: infinite;
}
/* Chrome, Safari, Opera */
@-webkit-keyframes shc {
  0%   {background-color:#3c53ff;}
  50%  {background-color:#24329a;}
  100% {background-color:#3c53ff}
}

/* Standard syntax */
@keyframes shc {
  0%   {background-color:#3c53ff;}
  50%  {background-color:#24329a;}
  100% {background-color:#3c53ff}
}