[jQuery] Opacity for a menu background, but not for the element inside

[jQuery] Opacity for a menu background, but not for the element inside


Hye,
I would like to create a menu, with a 80% opacity background, but I
want to keep the link element at 100% opacity.
For example :
<li><a href="link.html">lorem ipsum</a></li>
I would like to have the <li> element at 80%, but the <a> element at
100% (or 120%).
I know that I could use PNG, but it would be great if I could do this
with just a CSS Color and jQuery. Is there any solution ?