height being relative to chosen element

Do you know if I can choose the elem开发者_如何学编程ent which should be used to define relative height for other one?

The height by default will be relatively defined by its parent. Meaning that a nested div with height: 100px; will only ever be as high as the div it is inside of (not accounting for margins/padding).

You can use jQuery to set heights based on other elements.