Background takes it all over [responsive]

Hey there,

I’m making a new theme…

I got the basic of the background working pretty nice,
however, my theme is responsive, it’s working with mediaqueries.

The background is showing perfectly the way it should in desktopsize,
but when I want to see the smartphone/tablet-size (other mediaquery) the only, and I mean ONLY thing I see is the background… no content, no nothing.

Is there a method on changing this?
Is there something specific I need to add to the CSS or in function.php ?

There’s no difference in the mediaquery regarding the background-image.

Thank you !