#spinner {
  display: block;
  margin: auto;
  width: 32px;
  height: 32px;
  border-top: 2px solid #ccc;
  border-bottom: 2px solid #ccc;
  border-left: 2px solid transparent;
  border-right: 2px solid transparent;
  border-radius: 32px;
  animation: 0.5s linear infinite spinner;
  margin-top: 3em;
}

@keyframes spinner {
  0% {
    transform: translate3d(-50%, -50%, 0) rotate(0deg);
  }
  100% {
     transform: translate3d(-50%, -50%, 0) rotate(360deg);
  }
}