Gallery block not savings as a smaller size in mobile version

I'd like the gallery blocks smaller in height on the mobile version so you can see each image on your phone screen. When I try to adjust the height, it saves in the mobile version but then it'll alter the desktop version. Basically, I want the gallery block to be larger in desktop and smaller in mobile but the system isn't saving it. Is there a workaround or is there a bug of some sort?

For example, see page here https://www.biancamphoto.com/newborn. Desktop size is great, but if you pull it up on mobile it's too large.

Just now, biancamphoto said:

Thank you so much!! I thought this was a lost cause.

On 3/5/2023 at 12:33 AM, tuanphan said:

Add to Design > Custom CSS > then save & reload the site

/* Reels on mobile */
@media screen and (max-width:767px) {
.gallery-reel {
    height: 30vh !important;
}
}