_loader.scss

.lds-dual-ring {
  display: inline-block;
  width: 30px;
  height: 15px;
}
.lds-dual-ring:after {
  content: ' ';
  display: block;
  width: 20px;
  height: 20px;
  margin: 1px;
  border-radius: 50%;
  border: 2px solid #fff;
  border-color: #fff transparent #fff transparent;
  animation: lds-dual-ring 1.2s linear infinite;
}
@keyframes lds-dual-ring {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.loader-content {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: auto;
  text-align: center;
  height: 50px;
  width: 50px;
  background: rgba(0, 0, 0, 0.28);
  .lds-dual-ring {
    margin-top: 10px;
    margin-left: 5px;
  }
}