Inline Thumbnails For Max Mega Menu Submenu

Hello,

I want to create a submenu with Max Mega Menu, where the categories are on the left and the featured image thumbnails of my recent posts on the right.

This widget by default has each thumbnail on a separate line, and I really need to figure out how to make each image inline in a single row (with maybe 5-10px of padding in between).

I don’t need to add any other information other than the featured image thumbnail itself. I see a lot of bloggers successfully manage to do, but I can’t figure it out. Can anyone help me with this?