Font Rendering / Line-Height Issue on Mac/PC (outside of element)

Question

The Design

The info widgets content should be vertically aligned in the middle as such:

Answer 1

The Mac correctly displays the lengths below the baseline as belonging to line height. It seems that OS X counts bottom up whereas Windows calculates from the Top.

Since 1em is the width of the capital M of the used font it is usually smaller than the font's overall height.

Have you tried setting the line-height to be the same as the element height? This usually helps solve these kind of problems.