Adding image to header

Hello, I am trying to add a logo image behind the header text. I’m not sure why a theme would not allow this, yet no matter what I add into the CSS box PaperCuts provides, my image will not show up, even though it works just fine in the Google editor.

This is going to determine whether or not I use this theme, since the theme forces you to either use an image with no text, so on a mobile device the text is too tiny, or choose text and not have the option for an image. :/

Here is the CSS I am using:

#wrapper-header .header-content { background-image: url("urltoimagehere.png") !important; background-repeat: no-repeat !important; background-position: center top !important;}