Bug in the System

I think there is a bug in the system. I am currently kearning to design a button and it isn’t letting me submit the answer because it is saying the text-decoration hasn’t been done but in the css. page I have my link connected to it and everything and it says
a {
and it is saying I haven’t done it right.

Please remember to post a link to the exercise in question when starting a new lesson relatated topic or reporting an issue. Thanks.