Place this in the site wide css for the website. I put it in the site-wide body start code. It’s not perfect, but close….
.bwg-background, .bwg-background-0, .bwg_container, .bwg_thumbnail, .bwg_slideshow, .bwg_slide_container_0, .bwg_slide_bg_0, .bwg_slider_0, .bwg_slideshow_image_container_0, #bwg_container1_0, .bwg_slideshow_image_container_0 img{
max-width: 99vw!important;
background-color: #e6f1ff!important; /**use a bg color to match your page **/
}
@media only screen and (max-width: 900px) {
.bwg_image_info, .mCustomScrollbar, ._mCS_1{
margin:0!important;
padding:0!important;
}
.bwg_image_info, .mCustomScrollbar, ._mCS_1, .mCSB_container{
width: 100vw!important;
text-align: center!important;
}
.bwg-icon-times-sm, .bwg_close_btn{
font-size: 2rem!important;
}
}