Remove margins of "search store" section on small screen sizes

I'm trying to remove the margin around the "Find your local centre" on small screen sizes so the map on the page is not visible below it on bottom and on the sides.

I've tried using this, but it is not working:

@media only screen and (max-width: 900px)
#sl_find_a_store > span {
margin: 0 5px;
}
#sl_find_a_store{
border-radius: 0px !important;
margin: 0 -10px -5px;
}
}