css layout lib using flexbox
Based on the idea of a StackPanel (java, WPF), where every layout is composed via "jagged" stack-panels. So maybe you start out with a horizontal stackpanel which defines properties of some columns and then 1 or more of these columns contains stackpanels them selves (which again can contain stackpanels).
The combinations are endless and gives you an easy way of layout out your content with the precise alignment and sizing you want.