.loading span {
    background-color: #FFFFFF;
    background-image: url("../img/loading.gif");
    background-position: -8px center;
    background-repeat: no-repeat;
    border-radius: 100px;
    display: block;
    height: 180px;
    left: 50%;
    position: absolute;
    top: 75%;
    width: 180px;
    z-index: 9990;
}

.popup_span {
  display: block;
  top: 50%;
  left: 40%;
  position: fixed;
  background-color: transparent;
  z-index: 9999;
}

@media (max-width: 767px) {
    .loading span {
      left: 25%;
      top:75%;
    }
  }