Mobile display shows only half the screen

Here’s how it looks on android with Chrome browser. The default browser had an error.
http://postimg.org/image/mfmt446yp/
It might be that the site recognizes a mobile browser and shrinks the page to a certain dimension even if your phones browser can handle something bigger.

I have a feeling this has something to do with css media queries.
Try this in your child css.

@media screen and (min-width: 600px) {
	.site-content {
		width: 90%;
	}
}

That will tell me if I’m on the right track.