If your slightly strange CSS code works on all browsers on Windows, will it work on Mac and Linux?

Question

I am testing some weird-looking CSS code that I wrote (I'm using a mix of percentages and pixel values for width of DIVs, basically). While I'm not convinced that it's right, it works perfectly on all screen sizes on IE 5.5, IE 6.0 (thanks to these guys!), IE 7.0, Firefox 3.0 and Safari 3.12... all on Windows XP. Do I need to further worry about testing the code on Mac and Linux, or will it most likely work on these two without fail?

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Edit:

After a few months of working with this problem, I've found that Safari and Firefox are amazingly consistent between Mac and PC.

Answer 1

will it work on Mac and Linux?

Not necessarily.

Font rendering is the biggest issue with that sort of cross-platform. Some fonts that are available on Windows are not included in others by default and OSX has a very heavy font-rendering model (though Safari on Windows should show this - at least it used to).

General box models, padding, margins, et al should all be standard.