body {
  background: #eee;
  padding: 10%;
}

#button {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: #fff url("http://scottyzen.com/button/images/finger-print.png") no-repeat center;
  background-size: contain;
  display: block;
  margin: auto;
  position: relative;
  box-shadow: 0 1px 10px 0 rgba(1, 1, 1, 0.2), 0 1.5px 4px 0 rgba(1, 1, 1, 0.2);
}
#button:hover span {
  display: block;
}
#button span {
  border-radius: 50%;
  display: none;
  position: absolute;
  width: 160px;
  height: 160px;
  top: -10px;
  left: -10px;
  background-image: url("http://scottyzen.com/button/images/3.png");
  background-size: contain;
  z-index: -1;
  animation: spinner infinite 5s;
}
#button span:nth-child(2) {
  background-image: url("http://scottyzen.com/button/images/2.png");
  animation: spinner infinite 6s;
}
#button span:nth-child(3) {
  background-image: url("http://scottyzen.com/button/images/1.png");
  animation: spinner infinite 4s forwards;
}

@keyframes spinner {
  0% {
    opacity: 0;
    transform: rotate(0deg);
  }
  20% {
    opacity: 1;
  }
  33% {
    transform: rotate(-180deg);
  }
  66% {
    transform: rotate(720deg);
  }
  100% {
    transform: rotate(0deg);
  }
}