No worries… I really and truly wish I can help everyone who wants to do custom changes with themes, but anything “custom” someone wants to do falls out of support. The closest I could do is point out where code is located in files or what files to look into and then let the person have fun with code.
Regarding adding a background to menu links, what I can do is provide you with the container you can do that to if it’s the full container that you want to add it to.
