Centering Overflowed Element

左右に飛び出す可能性のある要素を水平・垂直センタリングを行いたい時、その要素の中央を親要素の中央と合わせるにはどうするのか。

top/right/bottom/left

keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out

常に左寄せになる。真ん中合わせの方法を思いつかない。

relative

keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out

自然に真ん中合わせになる。ただしラッパー要素が必要かつバグあり。

translate

keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out keep out

translateを使うバージョン(via @terkel)。自然に真ん中合わせになる。relativeより要素が少なくて済む。