I am trying to create a layout where the vertical spacing between divs is pixel perfect. So far I've ruled out almost all the big grid systems (960.gs, Blueprint), because they have no solution at all for the vertical spacings. With them, the only way to set vertical spacing between divs is to use body { line-height } attribute and manipulate the div spacing using that. I wouldn't call that a solution, as it ruins your template, depends on font-family, and doesn't let you use different spacings for different divs.
The only grid system I found which has proper support for vertical spacing is Golden Grid, which doesn't use body { line-height }, but has it's own .clear { height: 5px } for vertical spacing.
My problem is that no matter how I try, I couldn't make spacing work in HTML5. I am talking about vertically arranged images without gap between them. In XHTML transitional mode, everything works perfecly, the images align perfectly, but when in HTML5 mode, they have a vertical gap between them. The gap is 2px in Chrome and 2-3 px in Firefox, alternating between lines. I think it's the case with every grid system when used in HTML5 mode. I don't know what's the best way to write this code in plain HTML5, so I just tried grid systems. The vertical gap is present in 960.gs, Blueprint too.
A solution I found out might be to set body { line-height: 0 } and define line-height in every single typographic tag. But I don't understand why such a bad hack would be required for such a simple case: vertically arranged images. Why are browsers different in HTML5 mode than in XHTML Transitional mode?
Here, I have the same page, nothing changed, just the doctype. The XHTML one is pixel perfect in every browser, the HTML5 one has the gap and is different from browser to browser.
What is the best way to make the HTML5 example work like the XHTML transitional one?