Tagline enhancement

I am trying to enhance the Tagline on my site http://www.kmg-s.com/blog/ I have searched long and hard and tried adding various forms of the below into the style sheet:

.description {
color:#FFF;
font-size:90%;
float:right;
margin-right:5%;
text-align:right;
}

As explained in this post: http://wordpress.org/support/topic/108593 curtsey of vkaryl.

can anyone offer any further help or point me in the right direction?

Thanks in advance

The struggling beginner