Simplistic Theme Overriding Site Template CSS

Hello,

Seems the Simplistic theme overrides the site template's CSS theme elements, particularly as it relates to font face and size. I don't notice this in the other templates.

What is best practice for overriding the following elements in style.css to allow my site's template to control:

#discuss-wrapper {
font-family: 'Lucida Grande', 'Gisha', 'Lucida Sans Unicode', 'Lucida Sans', Lucida, Arial, Verdana, sans-serif;}

Thanks,
Preston