Replicate thumbnail formatting from Desktop to Mobile

ljk

Hi, this is my first post. I am going crazy... I formatted my website for a gallery to be two square thumbnail images, fixed at 960 pixels. It looks perfect on the desktop platform.On the mobile platform, it's a for of three tiny thumbnails. I would like it to have the two images side by side with a little space in-between the square images, just like the desktop platform. None of the other gallery styles work, as if it works on the mobile it doesn't work correctly on the desktop. I am very frustrated with the limitation of the thumbnail gallery style. Would be so grateful if someone could help me with CSS codes on how to fix this. This is a standard style in many other artist/photographers websites and am baffled that I have to go through all this trouble to try to adjust this. Thank you!