Change height of top gallery

Hi, 

i'm looking to change the height of this gallery block at the top of the page to max. 50% of the viewing height. 

Any tips on css code? 

https://pepper-magenta-kj7h.squarespace.com/

login: lapvergeten

Try adding this to Website > Website Tools (under Not Linked) > Custom CSS
 

[data-section-id="63ce8d3f4bbf4544dfc33bc3"] {
    min-height: unset !important;
    height: 50vh !important;
}