Code for changing no. of columns from 3 to 1 when going from desktop to mobile on a project page gallery

Site URL: http://www.dove-stingray-szey.squarespace.com

Hey, 

On each portfolio page I have a gallery block at the bottom of the page with 'related works'.  

I would like to keep the 3 columns on the desktop block, but change the block to 1 column when on the mobile site.

Is there a code to do that? and a code that works for all gallery 'grid:simple' blocks on the website?

Thanks

James 

Hi,

Your site is private. Can you setup password & share url again?