Link underline thicknesses are inconsistent

[abevoelker]

Maybe it's just my wonky Linux machine and its fonts, but link underlines seem to vary in thickness. On my machine, the "Pixyll in Action" demo post shows the issue:

Note how the thickness underlining on the "harmony of a paragraph" changes as the line breaks.

This became noticeable on a blog post I wrote where I have an unordered list of links close together: