Vertical centering usually requires weird hacks (either you know the height in advance and use negative margin, or use tables / display:table)

The part that annoyed me is the vertical centering is not preserved on window resize.

It can be done with flexbox now[1]. Which IE11 also supports[2] :)

[1]http://css-tricks.com/centering-css-complete-guide/#center-v... [2]http://caniuse.com/#feat=flexbox