We needed a lightbox effect for showing YouTube videos such as JJ's intro to the project on the home page. After looking at the excellent CSS Ninja FutureBox, I decided to implement something even simpler based on the target pseudo-attribute, and it's now working, using pure CSS. PS has enhanced the styling and it seems to be working well and looking good. It's based on a TEI <media> element, and although I have yet to document in detail how to do the markup, it's very simple, and anyone could look at the code and re-use it.