Is this sort of navigation possible to code using CSS? Using CMS.
 

Hi guys,

I'm building a website using CMS (so the navigation is a block), I'm sort of new to the system. I want to make the left navigation look something like THIS. See how the headers expand? I know it's entirely possible normally, but I have no idea how to implement that using a block in CMS. I have no idea how to make the headers expand while still using the same block.

Could you guys please help me out?

Thank you so much!