Change Columns in Only One Gallery on Page

Site URL: https://cat-wedge-xh9c.squarespace.com/about

I have two gallerys on my 'About' page - one for staff and one for our BOD. I want only one of these - the BOD - to display in three columns on mobile. By using this code : 

@media screen and (max-width:800px) {
.gallery-grid-wrapper {
    grid-template-columns: repeat(3,1fr) !important;
      grid-row-gap: 3vw !important;
}
}

I can change it to three columns, but it changes both of the blocks on the page. 

Can someone tell me how to just specify that one section that I want to change? Thanks!

Website: https://cat-wedge-xh9c.squarespace.com/about

You can add the section-id at the beginning of the code to specify just one section. Your BOD section-id is:

section[data-section-id="5f3ade67dd95661b3526a38e"]

I use Heather Tovey's Chrome Extension Squarespace ID Finder to make finding those fast and easy.