Centering with the flexible box model

from blog Oliver Caldwell's blog, | ↗ original
For those of you that have not heard of the flexible box model, brace yourselves. When it is more widely supported you will no longer need to silently (or audibly) scream to yourself when vertically centering a variable height block level element. But it does more than just center any way you want. It also allows you to center multiple elements...