Fredy-san
yes you can.
you can move the media box to behind using position:fixed;z-index:-1; then set the width and height to 100%
However, I do not recomend it. Because:
1. Different browsers treat the position different
2. It annoys ppl.
Um. Yeah, what you're saying to do makes no sense. All browsers treat a fixed positioned element the same. Changing the z-index is not necessary nor is changing the height and width. All you have to do is absolutely position the element, doesn't even have to be fixed, and move it to the left off the screen. Changing the height and width is unnecessary. Alternatively, you can absolutely position it and change the visibility to hidden.
xd
@OP~ Anyway, Fredy is right, it's very annoying and highly discouraged.