#loading_overlay {
  display: flex;
  position: fixed;
  top: 0; bottom: 0;
  left: 0; right: 0;
  align-items: center;
  justify-content: center;
  background-color: #FFF;
  z-index: 99;
}

@keyframes rotate360 {
  from { transform: rotate(-5deg); }
  to { transform: rotate(5deg); }
}
#loading_overlay img.loading {
  animation: 1s rotate360 infinite ease-in-out alternate;
  max-width: 51%;
  z-index: 1;
}