One step closer to "Tabless" workflow
Many years ago I embraced “tabless” development workflow: I use buffers, when I’m in Vim; I also switch tabs off in both Goland and VS Code, as the first thing after I install the IDEs to a new laptop.
I’m trying the same with Firefox web-browser now:

Enable
toolkit.legacyUserProfileCustomizations.stylesheets
switch in Firefox’s config (viaabout:config
page or insideuser.js
).Place the styles below into
%PROFILE%/chrome/userChrome.css
(I pick the actual path to the profile directory from Firefox’sabout:support
page).
// Hide the tabs.
// Beware that hidding the tabs with "display: none" will ruine you browser's recent history,
// I've learned that in a hard way ;)
#TabsToolbar > .toolbar-items {
opacity: 0;
pointer-events: none;
}
// Pull the navigation bar up, on top of the empty space, that left after we'd hidden the tabs.
#nav-bar {
margin-top: calc((7px + var(--tab-min-height)) * -1);
}
// On macOS, when not in full screen, shift the urlbar's panel to the right,
// after close-minimise-expand buttons.
:root:not([inFullscreen]) #nav-bar-customization-target {
margin-left: 65px;
}
I looked at mozilla-central/··/navigator-toolbox.inc.xhtml to get the structure of Firefox’s UI.
Pick some nice and clean theme. My kudos to Safari - MacOS Monterey Light by a person nicknamed notcat.
(Optional) In Firefox’s “General” preferences, switch off “Ctrl+Tab circles through tabs”. With that, pressing Ctrl+Tab exposes all currently open pages (similar to how on macOS or other OS one switches between the opened applications with ⌘+Tab).
Overall I’m fairly happy with how it ended up. Although, some things aren’t quite ideal yet (might add more as I use this setup):
I wish there was a shortkey to enter a “modal mode”, where I could filter the list of open pages, to search for a particular page, and to switch to this page. Something similar to :ls
command in Vim, or ⌘+E in Goland. I can use Firefox’s “Search amongst Tabs” for that (press ⌘+L to focus into the URL bar, and querying with “%[space]”) but that requires some getting used to.
Firefox has “Show all tabs” button (Ctrl+Shift+Tab) but the way it works, at least in Firefox 91, is very confusing and random. It seems to me, its behaviour is tightly coupled to the browser’s Tab UI.