Can't get underlines to work on links in posts

I'm old fashioned and am trying to get links in the text of my forum posts to be underlined. I have added to my CSS tab the following tetx:

a:link {color : #a30016; text-decoration: underline;}
a:visited {color : #a30016; text-decoration: underline;}

but only the category links on the home page display with an underline, the links in the posts do not.

Does anybody have any tips about how to get the links in my post texts to display the underline.

I'm using phpbb2, default style.

Hello,

You can use this code.
Add it to Admin CP > Display > Colors > CSS

Code:

.post a {
text-decoration : underline;
}

Thanks Anikillien. It initially didn't work but I changed your "a" to "a:link" and I now have underlines under my links in posts.