.loader {
  display: none;
  width: 100%;
  height: 100%;
  z-index: 1000000;
  position: fixed;
  left: 0;
  text-align: 0;
  top: 0;
  background-color: rgba(0, 0, 0, 0.1);
}

.loader > span {
  border: 6px solid #f3f3f3;
  border-radius: 50%;
  border-top: 6px solid #454545;
  width: 50px;
  height: 50px;
  -webkit-animation: spin 2s linear infinite;
  animation: spin 2s linear infinite;
  position: fixed;
  left: 50%;
  top: 50%;
  margin-left: -1em;
  z-index: 1000000;
}

/* Safari */

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

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