scaled-proportional-blocks-with-css-and-javascript css tricks
The web is a fluid place. Different sized screens, yadda yadda yadda. Fortunately for us, the web is ready for it. Text wraps. CSS gives us control over how to size things. What we don’t get (easily, anyway) is a way to scale whole element (and it’s children) proportionally—retaining its exact layout as it changes size.
https://css-tricks.com/scaled-proportional-blocks-with-css-and-javascript/