How to stick the vertical floating interface to the frame (relatively)?

Friends,

Million thanks for such an amazing plugin! It works like a charm.
I have a small improvement on mind. The vertical interface is placed absolutely and stuck to the left margin of the browser (though its alignment can be changed).

I would like it to stick to the frame with the text, so that when the browser size changes, it still stays stuck just on the left wall of the main frame (window) of my site.

Is that possible somehow, please?

Thank you, my heroes!

p.s. I’ve gave you my five starts time ago.

The page I need help with: [log in to see the link]