Flexbox Containers, PRE tags and managing Overflow

I've been moving a bunch of old markup over to Flexbox layout recently, because it makes so many things so much easier to deal with. One place I did this with is this blog – previously I was using a left float with absolutely positioned headers and containers, which worked Ok but was a nightmare to maintain. Moving that code to use a simple flexbox grid to manage the alignment greatly simplified the layout. The complexity of the CSS is greatly reduced and the page behavior is much more consistent across viewport sizes. Big win!