I'm not an expert on layouters, but I'm pretty sure that in the general case the height of an element does in fact depend on how it is layouted including what e

I'm not an expert on layouters, but I'm pretty sure that in the general case the height of an element does in fact depend on how it is layouted including what elements it is layouted with. I also believe that's why some traditional UI toolkits have started adopting constraint solvers. CSS can be frustrating and it was certainly for many years missing basic stuff, punting that to developers to solve by hand - but I agree with grandparent that these problems are not as trivial as they appear.