I'm not sure, but when I see how it looks now (resized to the edges), it doesn't look too good. Too much useless space on both sides of the sliders... On my previous screenshot it looks a bit cleaner. I think, I'll just go with shrinking that area where panels should show. As I said before, I don't wanna make everything look too crowded. Dotted line will be removed, but brown outline in those sliding panels must stay. EDIT: or, maybe I'll remove that one too, I have to check few things first...
Animation of those sliders will be simple in this one... or something like avast! Brushed, or completely without animation (or as less movement as possible)...