In most cases, flow layout works as you would expect it to when changing the writing mode of the document or parts of the document. This can be used to properly typeset vertical languages or for creative reasons. CSS is making this easier by way of introducing logical properties and values so that when working in a vertical writing mode sizing can be based on element's inline and block size. This will be useful when creating components which can work in different writing-modes....normal flow behaves, assumes a horizontal writing mode. Layout properties...property accepts the values horizontal-tb , vertical-rl and vertical-lr...