Background image as multiple tiles or partly seen

[strawpants]

First, thanks for the nice theme, I'm in the process of customizing it for my own homepage.

I noticed that the background image does not cover the webpage correctly. The website either shows a part of the image (if the image is hires) or there are multiple copies of the background image tiled together (when image is lower res than screen).

I tracked it back to the commit 5b87410 in static/css/styles.css.

When I change back the comment:
body::before { /*background-image: url('{{ .Site.Params.background }}');*/

to
body::before { background-image: url("/images/background.jpg");

it works again, but of course at the cost of being able to have an arbitrary name for the background image (i.e. the background param in config.toml has no effect). I don't have an elegant solution to fix this, but maybe you do.