Regarding some CSS style changes

[CruiserCommando]

I CANNOT for the life of me figure out how to change the font size of the pagetitle description that appears underneath the pagetitle of the forum when you are in that particular forum. I have put the following into addtional.css with no result:

#pagetitle .description {
font-size: 14px;
}

I have done some variations, such as .pagetitle .description and so on.
when I look at the page source code, it says the font is 11px, but it looks way tiny, there seems to be no direct way to change this in the style variable editor.

I have been successful at changing many of the elements of the style that I am using, including font sizes, but this one is eluding me. someone please help, as I have spent a lot of pointless time on this with no result. thank you for your time.