how to place a fixed banner stripe across the top of every site

We're loving your multisite plugins and all you offer.... hope you can assist with this.

We have been placing a banner stripe across the top of each of our Joomla sites in a fashion similar to your admin bar - see this site:

http://master.shopcen.co/

The css to do this is as follows:

#top-banner {
position: fixed;
top: 0;
left: 0;
background-color: #990000;
color: white;
font-weight: bold;
text-align: center;
width: 98%;
z-index: 999;
}

(I hope that is how you paste code here.... first timer :slight_smile:

is there an easier way to do the same with all sites created in all our multisite Marketpress sites?