I am in the enviable position of being able to say "Not using a modern browser, sorry, my site is not for you. Upgrade to a latest browser or leave." That doe

I am in the enviable position of being able to say "Not using a modern browser, sorry, my site is not for you. Upgrade to a latest browser or leave." That does make using Flexbox a whole lot easier. Having said that, Bootstrap 4 has optional Flexbox.