CSS: Make a block element fill the entire space of a parent element?

Question

I am trying to put a link in a element and have the element fill the entire space of the . While I can

Answer 1

As @Hober says, you need to give the a height. You could also use height: 100% there.

If you know the dimensions of your , which it looks like you probably won't in this case (since they're on the side), I've had luck adding a padding to push the out to the edges (past any padding from the itself), and then bringing it back in with a corresponding negative margin. Like this:

th a{
  padding: 10px 0;
  margin: -10px 0;
}