regression: Hover sectionLink components causes their sizes to change due to border

[alasdairwilson]

Annoyingly this breaks whatever I had to do to get them to not move when the hover border width changed:

versus new:

I have absolutely no idea why? There might be an easy fix but it could certainly be fixed using box shadow rather than border? well I am never certain about anything when it comes to frontend.

BUT, we will spin this into another issue cause I would rather have them move slightly than the current text-overflow that we have.

Originally posted by @alasdairwilson in #233 (comment)