Spinner

HTML

<div class="spinner">
</div>

CSS

@keyframes spin {
  to{
    transform:rotate(360deg)
  }
}
body{
  background:#20262e;
}
.spinner, .spinner::before, .spinner::after{
  content:'';
  display:block;
  border:4px solid transparent;
  border-radius:50%;
  animation:spin infinite linear 2s;
  position:absolute;
}
.spinner{
  width:100px;
  height:100px;
  border-top-color:orange;
  top:calc(50% - 50px);
  left:calc(50% - 50px);
}
.spinner::before{
  border-top-color:magenta;
  animation-duration:4s;
  top:2px;
  bottom:2px;
  left:2px;
  right:2px;
}
.spinner::after{
  border-top-color:cyan;
  top:8px;
  bottom:8px;
  left:8px;
  right:8px;
}