> there is special mechanism built in it Yes, a return to the dark days of UAs having their own proprietary extensions / prefixes to do the same thing. Why bot

> there is special mechanism built in it Yes, a return to the dark days of UAs having their own proprietary extensions / prefixes to do the same thing. Why bother when there's an actual industry standard? > You should not assume that all browsers support same set of features. You can certainly target only user agents which support CSS Flexbox. I would even say it's the advisable default unless you have some very special needs.