Just curious to see what length value types you all use for padding. margin, font sizes, etc. I personally use pixel measurements for everything. But I usually see a lot of the CSS gurus using percentages and ems. What's your preference?

Accessibility comes into play here also, which is why I'm asking.

It depends a little on the property. I think you're always better using 'em' or some relative measurement for font size. It's an accessibility issue for people who have a hard time reading your default font. Internet Explorer won't resize the font if you use px as the measurement. I'm not sure if that's still true in IE7, but I suspect it is.

For the rest I think it comes down to your design and what you want to achieve. If you're going after a fluid layout then some elements will need to use a relative measurement. If your design is a fixed design then fixed measurements would be preferable, but even there you may want certain parts of your design to be fluid even within the overall fixed layout.

I don't think there's any one answer here since the design itself can really be what leads many of the measurement decisions.

I'm firm though on using the relative measurements for font-size. I may use a fixed measurement in specific areas like a menu if changing the size could break the layout, but the main body content should absolutely be a relative measurement and in all honesty I should just work harder to ensure using relative measurements in places like menus doesn't break the layout.

Point taken with the font sizes. That was one of my biggest concerns.

It's funny too how it started to become more important to me as I got a little older and had a harder time reading smaller text.