overriding template css

I am trying to make all text links underlined. In the template, links are only underlined over hover. I went into custom CSS and added the following code:

a:link {
   text-decoration: underline;
}

It didn't work and I'm wondering if I need to add code that overrides the template hover request.

Thanks for the help.

That worked great I was able to customize the thickness and offset by adding the following code:

a {
   text-decoration: underline 2px     !important;
}

a {
  text-underline-offset: 3px;
}

Any way to have this code and remove it from the navigation bar? I like it on body/paragraph/heading text but not in the navigation.

Use this code under

header#header a {
	text-decoration: none !important;
}