Overide Focal point with CSS

Hi,

I'm trying to overide the focal point on my section background in mobile.... can't seem to find how to change it. Here's my CSS if it's any help. 

@media screen and (max-width: 640px){
  #collection-5e266f9cd88c7d1ea1362bbc{
    .section-background{
    min-width: 200%;
    min-height: 200%;
    ????: ????;
    }
  }
}