spinner.css

.spinner,
.spinner:after {
  border-radius: 50%;
  width: 1.5em;
  height: 1.5em;
}

.spinner {
  font-size: 10px;
  position: relative;
  text-indent: -9999em;
  border-top: .2em solid white;
  border-right: .2em solid white;
  border-bottom: .2em solid white;
  border-left: .2em solid transparent;
  -webkit-transform: translateZ(0);
  -ms-transform: translateZ(0);
  transform: translateZ(0);
  -webkit-animation: loading 1s infinite linear;
  animation: loading 1s infinite linear;
}

@keyframes loading {
  0% {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  100% {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}