[Bellardia]

Plugin
global_start

PHP Code:

$style[css] .= 'Your Style!'; 


Add the relative link to your style sheet and have them upload it

I supposed I should specify
It will insert it after the global css style, but outside of the <style> tags, so you can specify inline styles by adding more <style> tags followed by your css, or link it to the external css.

I'm not sure of a way to get it into the actual css if they're using an external page ):