What? Flex doesn't need a prefix and hasn't for ages (since version 20. It's on 50 now) Furthermore, it's best that features are behind prefixes to be used for

What? Flex doesn't need a prefix and hasn't for ages (since version 20. It's on 50 now) Furthermore, it's best that features are behind prefixes to be used for progressive enhancement and any major browser implements new features behind a prefix before it is accepted. There is no "cross browser hacks" for any evergreen browser. Except, ironically given your statement, IE has a buggy implementation. Edge supports it and Microsoft is deprecating IE<11 and will hopefully fix the issues in IE11. The big issues can be avoided by not declaring a min-height. http://caniuse.com/#feat=flexbox http://caniuse.com/#feat=flexbox