IMHO I think that one of the main problems with CSS is that it doesn't have an explicit model of text. If you have that, then a constraint-based designer can take you through wizards to ask to to consider eg. When there's more text than space. Springs, struts etc. Can take care of layout. Controversially I think we should replace/remove div tags as they don't make all their behavior explicit vs flexbox/ cssgrid etc. Every object should have explicit layout behaviors defined. Then you can compose them or create new objects for undefined cases.