XF 1.5 How to add xen:if in EXTRA.css?

[Stockwalker]

I would like to add some conditional styling in EXTRA.css, how do I do that?

 

[[xFv]]

<xen:if is="@properyID">

 

[JacquiiDesigns]

https://xenforo.com/community/threads/conditionals-in-the-extra-css.85287/