Being very much in a True Detach mood today, I share my current best recommendations to achieve this effect. Roughly in the order of bestness.
1. A minimal browserA minimal browser has minimal interface out of the box, basically just the title bar (mandated by the window manager) and the combined status+navigation bar. To achieve something like True Detach, just open such a browser. That's it. If you are extra lucky, it has a rendering engine that can play anything you need. More likely not though.
2. Pale MoonThis Mozilla derivative has a fabulous toolbarless mode that you can try out as follows:
- Under Preferences > Tabs, uncheck Always show the tab bar
- Under View menu, uncheck the Bookmarks toolbar, then the Navigation toolbar, and finally the Menu bar
What is left is something like a minimal browser. What's super awesome about it is that, in this state, Pale Moon has a popup secondary address field under the common keybinds Alt+d and Ctrl+l, so the browser remains completely usable without menus and toolbars.
A new tab and the tab bar opens up by Ctrl+t. By right-clicking on the empty space in the tab bar you will get your toolbars back. By the way, Seamonkey (the successor of Mozilla Suite) works the same way, except that the secondary address field is only under Ctrl+l.
This is an area where modern FF totally lost it.
3. OtterIn Otter, all toolbars can be hidden either by right-click or menus, like in Pale Moon, or by keybinds that you have to build. Otter has a less elaborate, but functional secondary address field. Additionally, there is a separate popup to go to bookmarks like in old Opera.
Honorary mention: Vivaldi browserUnder Tools > Settings > Appearance, Vivaldi has the Show User Interface checkmark. Vivaldi turns into a minimal browser by this setting. This is a fabulous setting, but it's better to make it into a keybind. Under Keyboard, find View > Toggle UI and put your preferred keyboard shortcut there.
With these settings, Vivaldi's interface morphs faster than Pale Moon's, but Vivaldi cannot earn a better place on this list due to lack of access to a (secondary) address field in this state. As far as I can see, to use the address field, you have to turn the interface back on.
I asked the question in Vivaldi forum and I got the reply: Quick commands. Indeed, Vivaldi's Quick commands do more than old Opera. You can search for anything in Quick commands, in this case for Address bar and select it and the address bar returns. While this does the trick, it is (a) slower than having a direct keybind to secondary address field and (b) loses the minimality.
Edit: Looks like the Quick commands field doesn't just search, but acts as a secondary address field just by typing a url in there. I guess I have to raise Vivaldi on this list
