I think they have at least 3 layers in use here,
the first one is for the sun and the blue sky thingy(this could be more layers then just one, but I do think it is on a different layer than the rest) this is in my idea the lowest layer(like the most to the background sent layer)..
the second one is for the reed, which I believe is a brush combined with a square....that should do the trick about the black part. I can't tell you which brush it is exactly but
this one is similar.
And on the third layer is the content of the site, with the buttons, which is I think regulated with javascript or so.
Hope this helps out a bit....
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