Really nice design. This GUI style has a bit of a Smalltalk-80 vibe, with the raster line shadows and old-style fonts.<p>A tiny observation... The examples box that peeks from the left-hand edge works great, but it's slightly confusing that it's showing the X button initially (when there isn't anything to close yet). How about making this icon initially display as a disclosure triangle (something like a > shape), and then morph into the X when the box is actually open?