If fixed width size is fine you could do this using floating menus (they will soon support this layout in responsive mode, but for now only fixed size windows will work).
Here is an example, if that is what you imagine I can give more instructions on how to adapt to your needs! webview-sidebar2.bttpreset (25.1 KB)
This example shows/hides when pressing cmd+opt+ctrl+W
Yes, that's exactly what I wanted. Thank you, Andreas.
A few questions:
How can I navigate in this browser (back and forward)?
The browser (the floating menu) always opens Google first, even if I change the order of the items. Can I change that? I would prefer it to open as it was last closed.
Can I view and edit a text document (RTF)? Just like in Clipboard Manager?