An alternative to font-weight for bolding text is to use text-shadow to set a horizontal shadow the same colour as the text. This code sets equal shadows to the left and the right. With only one shadow, the text would appear to shift in the direction of the shadow.
CSS:
a:hover {
text-shadow: .25px 0px .1px,
-.25px 0px .1px;
}
Note that web browsers do not render text, let alone text-shadow effects, identically. You'll want to check how they look in multiple browsers before deciding on values.
