The floating menu bar for my blog page is not showing up. Is there a way to make it show using CSS?

To Whom it May Concern,

I recently pasted a line of code into the simple CSS plugin. The code was as follows: .entry-content a[rel="category tag"]{
display: none;

The aim of the code was to prevent the category of each individual blog post from being displayed. Unfortunately, the code did not have that effect; instead, the result was that the floating menu bar in the main blog page (meaning the page that lists all of the individual blog entries) is no longer there. Do you have any suggestions as to how I can rectify this situation?

Thank you in advance for your help.