.cursor {
  height: 200px;
  width: 200px;
  background-color: rgba(0, 0, 0, .5);
  border-radius: 50% 50% 50% 50%;
  box-shadow:#333 0 0 10px, #CCC 0 0 20px;
  position: absolute;
  z-index: -1;
  animation: linear 5s infinite cursor;
}

@-webkit-keyframes cursor {
	0%{ transform:scale(1); opacity:0.5;box-shadow:#333 0 0 10px, #CCC 0 0 20px;}
	50%{ transform:scale(0.8); opacity:1;box-shadow:#000 0 0 10px,#333 0 0 15px, #CCC 0 0 30px;}
	100%{ transform:scale(1); opacity:0.5;box-shadow:#333 0 0 10px, #CCC 0 0 20px;}		
}