Board Thread:Support Requests - Designing Your Wiki/@comment-39124658-20190707045510

I have a navbox that I want to add to it, an image as a background. Is it necessary to edit CSS, or how can I do it so that it has a background image?

[//wubbzy.fandom.com/wiki/Template:Main-A https://wubbzy.fandom.com/wiki/Template:Main-A]

PD: How do I make sure that the template does not ruin the bottom part? 