How to resize banners heigh for mobile

Site URL: https://www.vivoanimationschool.com/it/personaggi

Hi, I am using Squarespace 7.0 with Foster template. Do you guys know how to resize the banners in my pages only in the mobile view? Thank you

It looks like you used 2 banners for desktop/mobile. However if you want to resize desktop banner on mobile. Remove your code & add this CSS

/* resize mobile banner */
@media screen and (max-width:640px) {
section#banner-desktop figure img {
    width: 100% !important;
    left: 0 !important;
    height: auto !important;
}
section#banner-desktop {
    height: 220px;
}
}