div.loader {
    margin: 20px;
    width: 80px;
    height: 80px;
    -webkit-animation-name: spin;
    -webkit-animation-duration: 2000ms;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-timing-function: linear;
    -moz-animation-name: spin;
    -moz-animation-duration: 2000ms;
    -moz-animation-iteration-count: infinite;
    -moz-animation-timing-function: linear;
    -ms-animation-name: spin;
    -ms-animation-duration: 2000ms;
    -ms-animation-iteration-count: infinite;
    -ms-animation-timing-function: linear;
    animation-name: spin;
    animation-duration: 2000ms;
    animation-iteration-count: infinite;
    animation-timing-function: linear;

    position: fixed;
    left: 50%;
    margin-left: -40px;
    top: 35%;
  }
  
  @-ms-keyframes spin {
    from {
      -ms-transform: rotate(0deg);
    }
    to {
      -ms-transform: rotate(360deg);
    }
  }
  
  @-moz-keyframes spin {
    from {
      -moz-transform: rotate(0deg);
    }
    to {
      -moz-transform: rotate(360deg);
    }
  }
  
  @-webkit-keyframes spin {
    from {
      -webkit-transform: rotate(0deg);
    }
    to {
      -webkit-transform: rotate(360deg);
    }
  }
  
  @keyframes spin {
    from {
      transform: rotate(0deg);
    }
    to {
      transform: rotate(360deg);
    }
  }