.loader{
  width:100px;
  height:100px;
  background-color:transparent;
  border-radius:50%;
  border: 12px transparent solid;
  border-top:12px blue solid;;
  border-bottom: 12px blue solid;
  animation: rotate 2s linear infinite;
}

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