Mobile Site cutting off my banner/photo on homepage

Site URL: https://www.wobblerealm.com/

My banner is being completely cut off on my homepage instead of resizing. How do I fix that?

https://www.wobblerealm.com/

Add to Home > Design > Custom CSS

@media screen and (max-width:767px) {
.homepage #page section:first-child {
    min-height: 30vh !important;
}
}