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.
The part that annoyed me is the vertical centering is not preserved on window resize.
[1]http://css-tricks.com/centering-css-complete-guide/#center-v... [2]http://caniuse.com/#feat=flexbox