/* Absolute Center Spinner */
.loader {
    position: fixed;
    z-index: 999;
    height: 2em;
    width: 2em;
    overflow: show;
    margin: auto;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
  }

  /* Transparent Overlay */
  .loader:before {
    content: '';
    display: block;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
      background: radial-gradient(rgba(20, 20, 20,.7), rgba(0, 0, 0, .7));

    background: -webkit-radial-gradient(rgba(20, 20, 20,.7), rgba(0, 0, 0,.7));
  }

  /* :not(:required) hides these rules from IE9 and below */
  .loader:not(:required) {
    /* hide "loading..." text */
    font: 0/0 a;
    color: transparent;
    text-shadow: none;
    background-color: transparent;
    border: 0;
  }

  .loader {

  }
  .loader:not(:required):after {
    content: '';
    display: block;
    font-size: 10px;
    width: 1em;
    height: 1em;
    margin-top: -0.5em;
    -webkit-animation: spinner 150ms infinite linear;
    -moz-animation: spinner 150ms infinite linear;
    -ms-animation: spinner 150ms infinite linear;
    -o-animation: spinner 150ms infinite linear;
    animation: spinner 150ms infinite linear;
    border-radius: 0.5em;
    width: 64px;
    height: 64px;
    position: relative;
    background-image:
      linear-gradient(#FFF 16px, transparent 0) ,
      linear-gradient(#FF3D00 16px, transparent 0) ,
      linear-gradient(#FF3D00 16px, transparent 0) ,
      linear-gradient(#FFF 16px, transparent 0);
    background-repeat: no-repeat;
    background-size: 16px 16px;
    background-position: left top , left bottom , right top , right bottom;
    animation: rotate 1s linear infinite;
  }

  /* Animation */

  @keyframes rotate {
    0% {
      width: 64px;
      height: 64px;
      transform: rotate(0deg)
    }
    50% {
      width: 30px;
      height: 30px;
      transform: rotate(180deg)
    }
    100% {
      width: 64px;
      height: 64px;
      transform: rotate(360deg)
    }
  }