CSS actually already accounts for that with it's "inline" and "block" axes. Where inline is the axis along which text flows first (horizontal by default for lat

CSS actually already accounts for that with it's "inline" and "block" axes. Where inline is the axis along which text flows first (horizontal by default for latin text - although this can be overiden with the writing-mode property), and block is the other axis. Flexbox's main axis controlled by flex-direction is an extra abstraction on top of that.