★ 'Floating' toolbars ★ with autohide! - Hide Caption Titlebar Plus ⁴ addon
The latest exceptional features of "Hide Caption Titlebar Plus ⁴" addon for Firefox, Waterfox, Pale Moon and other similar browsers!
Showed with 'Small Tabs' & 'Small Toolbars' features on. With near-default widgets arrangement.
(They can be of course relocated to any bar by using 'Toolbars » Customize', including menu)
Tabs in multibar form is from 'Tab Mix plus' addon.
You can try this and see all info here:
https://tiny.cc/hidec