CSS calc not working in Safari and fallback

Question

I have this layout I am working on. It strongly depends on CSS calc to do the necessary calculations.

width: -webkit-calc(50% - 20px);
width: -moz-calc(50% - 20px);
width: calc(50% - 20px);

Now, I can't get this to work in Safari. Is there something I'm doing wrong?

And also, is there a way I can introduce a fall-back mechanism for browsers that don't support it? Percentage wont do a good job, since I have to subtract the object in the middle, from the two on the side.

Thanks.

Answer 1

The way I solved this problem, is introducing a pure CSS fall-back, that older browsers that don't support CSS calc would only read.

figure.left {
    width: 48%;
    width: -webkit-calc(50% - 20px);
    width: -moz-calc(50% - 20px);
    width: calc(50% - 20px);
}

The left and right panels, get a width of 48% if the browser cannot read the calc values.

figure.logo {   
    min-width: 40px;
    width: 4%;
    width: -webkit-calc(40px);
    width: -moz-calc(40px);
    width: calc(40px);
}

And the logo, which sits in-between the two panels, gets a width of 4%. And also a minimum width of 40px. And if the calc values can be read by the browser, they are 40px.