First, take a minute to read this QuickTip as it put the following into context for you:
The last paragraph is key to the answer for you.
My suggestion is to duplicate the
circled.css file, name it
circled-single.css and place it one of the paths noted in the QuickTip. You can then tweak that CSS file as needed. Since it loads after the
circled.css, any changes you make in the new single file will be overridden.
Hope that helps!