#img-qr {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, 50%);
  padding:25px;
  background-color: white;
}
@media screen and (max-width: 480px) {
  #img-qr {
    position: static;
    top: 0;
    left: 0;
    transform: none;
    text-align: center;
  }
}