Making the gallery 100% width for mobile phone

Hi there, love this plugin, but what I would like to achieve is to have the gallery images stack at 100% when viewed in a mobile phone, instead of resizing and showing in 3 columns. I have several posts set up with image galleries showing in 3 columns and when clicked to pop up the image larger, which is great for desktop viewing. is there any solution to this? Thanks in advance
Here is the url https://www.sanneart.com/portfolio/people-2/