Vertical centering isn't that useful when you already have to know the height of things... I mean, if you already know the heights, you can just put the numbers in straight.

The best way to do real vertical-centering that works with variable heights, and doesn't use JavaScript, is to take advantage of the fact that table cells do this with "vertical-align: middle". Inexplicably, only table cells allow true vertical centering with variable heights.

So you can either convert the surrounding element to a big ole <table><tr><td></td></tr></table>, or you can use CSS to give it a property of display: table-cell. And in both cases, give it a "vertical-align: middle". Then you're good to go!

And of course, horizontal positioning in the table cell is easy.