How to remove underline from links 

Hi, I’m simply trying to figure out how to remove the underline from hyperlinks. So far I’ve tried inserting the following code without success using the WP Add Custom CSS plugin.

.entry-content a {
border-bottom: none;

I’ve also tried clearing both my browser’s and my site’s cache to no avail. Is there a simple way to do this? (using Moka theme)