Looking to build an expand on hover/contract on blur div

Question

Hey all, I\'ve been beating my head against the search engine walls for a couple hours now and figure I might as well just ask...

I need to build a div that is one s

Answer 1

If you add a transition to Robert's answer, it's CSS-only, and you get animation, too:

Add this to the div (not the div:hover): transition: height 0.5s ease-in;

I just implemented this on a site, and it even works well for mobile. The div does have to be a static height when collapsed and expanded, though.