pseudo elements a:after a:before allow you to add text that appears to be part of the link. However, I can't seem to figure out a way to make that portion clickable as part of the link.
For example the following css shows the url afterward:
content: " (" attr(href) ")";
It looks like you have discovered a bug in the browser you are using.
Based on the spec, the generated content should be treated as a child of the element it is being generated for. I created a JSFiddle to test this out, and the generated text is linked for me in most browsers (Chrome 13 being the solitary exception.) My guess is that you are testing in Chrome. This is a reproducible bug.
The workaround is to simply specify a background color on your links ... if you want to be able to use this for all links, declaring a background image (but not specifying an image, or using a transparent
.gif - or as just pointed out, setting
opacity to anything other than 1) works.