One of the designs I recently had to work on needed a narrow width header in a sidebar with a large number on the left side of it and the header text vertically centered to the right.
If you've worked with CSS for awhile you've probably ran into the same issue as everyone else. Vertical alignment with universally supported css is not easy. There are multiple techniques you can use to make something vertically aligned but there are drawbacks to each.
For my use case I couldn't use any of the normal tricks I'd use. I didn't know the exact height of the number and I needed the header text on the right to wrap properly. So I couldn't use a typical technique involving line-height, absolute positioning, or padding.