.loader {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  box-shadow: rgba(0, 0, 0, 0.4) 0px 2px 4px, rgba(0, 0, 0, 0.3) 0px 7px 13px -3px, rgba(0, 0, 0, 0.2) 0px -3px 0px inset;
  animation: rotate 2.0s infinite linear;
}

@keyframes rotate {
  100% {
    transform: rotate(1turn);
  }
}