You probably don’t need the li in the first part. The second part could be #nav .item. Off hand, I think that this will do the job. It may depend on other rules that we can’t see.
I think I figured it out. It has to do with the rules of Specificity.
I am working on Joomla extension that could be installed in any number of websites that could have lots of different templates and div names. Which is why I had need to be able to override code that the website may already have. So in this instance the div is called nav another template could call the div a different name.
I found this specificty post and realized I needed to have an ID selector included in my statement in order to be able to override the template statement.
by adding an id also included in my code I was able to override the #nav line.