Okay everyone, new here, of course, and as much as I hate to be one of those people that don’t really know much about a topic at hand and gratuitously seek out the help of those who do, here I am. 
The upshot is that it’s probably something really easy to answer for those who know Javascript already. 
I’ve tried figuring this out but I’m at a loss. I can manage pretty well with CSS, messing around and playing with values to figure out what I need, but I’ve taken a look at the Javascript and it’s completely unapproachable for me. I used a website, CSS Menu Generator - Horizontal, Vertical, Drop Down, DHTML CSS Menu to create a really nifty dropdown menu, which has a tree structure in Javascript as well as collapse and expand buttons. The great thing is that, for those with Javascript disabled, it still fully works as a CSS drop-down menu.
But I’ve been asked to modify it. Right now, you click and that’s how things expand. But I’ve been asked to make it so that it will expand simply on hover.And I don’t know what to do at all. 
Of course I know how to change the colors of the particular fields when you hover, through CSS, but to make it expand simply on hover? 
Think anyone can give me some pointers or a bit of help? The website in question is here Psiholog Popa Anca. Great job on the colors though, eh? 
Let me know! 