I can't seem to recollect how to do this CSS only trick where one can hover over an element and the effect of the hover stays forever. I know it had something to do with transition being set to 9999s meaning it will take forever to return back to normal, hence the end result stays. This is good for making css only dialog boxes to stay open.
Using the following HTML and CSS elements:
<div>
something here
</div>
CSS:
div { width: 100px: height: 100px; transition: all 9999s; }
div:hover { height: 300px }