Forum:Adding Background-image to an Infobox?

I feel really silly asking this, but how do you add a Background-Image to an Infobox? I feel like I've missed something obvious.

I spent a couple hours on the weekend designing (read: trying) a really nice Infobox in Photoshop, but now I can't get it into the Wiki. I'm trying to give the second black box the image: http://vampirewars.wikia.com/wiki/Template:Infobox_Ability http://vampirewars.wikia.com/wiki/File:Infobox_Image_Background.jpeg http://vampirewars.wikia.com/wiki/MediaWiki:Common.css


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