.loader_panel{
    /*background-color:gray;*/
    /*background: rgb(204, 204, 204);*/ /* Fallback for older browsers without RGBA-support */
    background: rgba(204, 204, 204, 0.5);
    z-index:9999;
    top:0px;
    left:0px;
    width:100%;
    height:100%;
    display:none;
    position:absolute;
}
.loader {
  border: 16px solid #f3f3f3;
  border-radius: 50%;
  border-top: 16px solid #3498db;
  position:absolute;
  left: 50%;
  top: 50%;
  margin-left: -30px; /* -1 * image width / 2 */
  margin-top: -30px; /* -1 * image height / 2 */
  width: 60px;
  height: 60px;
  -webkit-animation: spin 2s linear infinite;
  animation: spin 2s linear infinite;
}

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

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