html - CSS Calc Viewport Units Workaround?

Question

From what I've seen in other answers, CSS viewport units can't be used in calc() statements yet. What I would like to achieve is the following statement:

height: calc(100vh - 75vw)

Is there some workaround way I can achieve this using purely CSS even though the viewport units can't be used in the calc() statement? Or just CSS and HTML? I know I can do it dynamically using javascript, but I'd prefer CSS.

Answer 1

Before I answer this, I'd like to point out that Chrome and IE 10+ actually supports calc with viewport units.

FIDDLE (In IE10+)

Solution (for other browsers): box-sizing

1) Start of by setting your height as 100vh.

2) With box-sizing set to border-box - add a padding-top of 75vw. This means that the padding will be part f the inner height.

3) Just offset the extra padding-top with a negative margin-top

FIDDLE

div
{
    /*height: calc(100vh - 75vw);*/
    height: 100vh;
    margin-top: -75vw;
    padding-top: 75vw;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    background: pink;
}