Forum Condition that announcement doesn't appear in mobile style?

[محروم.كوم]

I have an HTML announcement that calls on specific CSS which is located in the additional.css template. This works fine on several styles I've created for the site. But it seems that the additional css isn't used in the mobile style (I've tried adding it, but it's not displayed properly) and the announcement is totally messed up looking. Is there a way that I can have an announcement not show up via a mobile browser? At the moment I have the mobile style turned off, but I'd like to use it. __DEFINE_LIKE_SHARE__