Current site default is to embolden links on hover. This causes transient re-layout, potentially on a large scale (as the emboldened link text is wider than than normal text). This, in turn, is distracting and irritating (to me!). This style does its best to override that. It also (added bonus?) underlines all links by default, restores the classic distinction between visited and unvisited links, and makes the default text color black (rather than a washed out grey that I find hard to read!).