Getting percentages to work in CSS calc() for Firefox and Safari?

Question

I\'m using the following calc() equation to calculate the width of two divs:

CSS

.MyClass {
    width: calc((100% - 800px) / 2);
    wid         


        

Answer 1

Works for me..: CSSDeck example --> in Firefox Nightly

Are you using a CSS-preprocessor, which could interfere with calc()? Have you tried to replicate the issue in a controlled environment (plain html + css without any scripts etc)?

EDIT: Also note that calc(100%-3em) might not work, while calc(100% - 3em) should.