Experimented with this a little more, I found out that the status bar is a ~60% opacity black bar, and the bottom portion has a shadow-like gradient.
I added a 40px black bar layer with 60% opacity that stayed at the top of the document, and made changes accordingly beneath it. The tricky part is the shadow at the bottom, but I impressively managed to make the illusion. It looks much more invisible on the iPhone than on a desktop:
I added a 40px black bar layer with 60% opacity that stayed at the top of the document, and made changes accordingly beneath it. The tricky part is the shadow at the bottom, but I impressively managed to make the illusion. It looks much more invisible on the iPhone than on a desktop: