There's no reason why constraint solving wouldn't work just as well in the browser as AutoLayout works on OSX/iOS if it was natively implemented. It is not nat

There's no reason why constraint solving wouldn't work just as well in the browser as AutoLayout works on OSX/iOS if it was natively implemented. It is not natively implemented however. Also, to take it further, Cassowary.js could solve for and output to flexbox as a backend.