.loader_bg {
  position: fixed;
  z-index: 9999999;
  background-color: #fff;
  width: 100%;
  height: 100%;
}

.loader {
  border: 0 solid transparent;
  border-radius: 50%;
  width: 150px;
  height: 150px;
  position: absolute;
  top: calc(50vh - 75px);
  left: calc(50vw - 75px);
}

.loader:before,
.loader:after {
  content: "";
  border: 1em solid #0f3f8c;
  border-radius: 50%;
  width: inherit;
  height: inherit;
  position: absolute;
  top: 0;
  left: 0;
  animation: loader 2s linear infinite;
  opacity: 0;
}

.loader:before {
  animation-delay: 0.5s;
}

@keyframes loader {
  0% {
    transform: scale(0);
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    transform: scale(1);
    opacity: 0;
  }
}