Edge-Frfox

A Firefox userChrome.css theme that aims to recreate the look and feel of the Chromium version of Microsoft Edge.

How to install

Go to about:support and click the "Open Folder/Show in Finder" button for the root directory of your browser profile/s.
Download and copy the chrome folder into the profile folder.
Go to about:config and change these preferences:

For all operating systems:
1. toolkit.legacyUserProfileCustomizations.stylesheets = true
2. svg.context-properties.content.enabled = true
3. layout.css.color-mix.enabled = true
On macOS:
1. To use the Edge style context menu on macOS then set widget.macos.native-context-menus = false
Recommended:
1. browser.tabs.tabMinWidth = 66
2. browser.tabs.tabClipWidth = 86
Optional:
1. To use the light theme in private browsing mode set browser.theme.dark-private-windows = false
Additional tweaks can also be applied to the theme, such as Mica (Windows 11 Only), Floating Tabs and more. See Tweaks.

Note: Most frequently tested on macOS

Screenshots

Theme	Light	Dark
Default (Windows 11)
Floating Tabs (Windows 11)
Mica (Windows 11)
Mica and Floating Tabs (Windows 11)
GTK (GNOME 42, adw-gtk3 theme)

Tweaks

Certain tweaks can be applied to the theme, to enable them navigate to about:config and create a boolean key for each tweak you want to use and set it to true, then restart the browser.

To disable a tweak, set the key to false or delete it, then restart the browser.

use background image on newtab page
SETUP: Add an image named `background-0.(jpg/png)` to the `chrome` folder.
OPTIONAL: Add a second image named `background-1.(jpg/png)` for seperate dark mode background.
`uc.tweak.newtab-background`

hide Firefox logo on newtab page
`uc.tweak.hide-newtab-logo`

disable drag space above tabs
`uc.tweak.disable-drag-space`

enable rounded corners
`uc.tweak.rounded-corners`

enable Edge style floating tabs
`uc.tweak.floating-tabs`
OPTIONAL1: Make the top and bottom margins of the tab equal
`uc.tweak.floating-tabs.equal-margin`
OPTIONAL2: Hide the separator of adjacent tabs (need to wait for Firefox support, or forced enable with bug)
`layout.css.has-selector.enabled`

enable Mica toolbar background (Windows 11 only)
See Mica Tweak Instructions for installation instructions.
NOTE: Only works on default theme: 'System theme - auto'
`uc.tweak.win11-mica`

force tab background colour to the same colour as the navbar background (useful for Proton themes)
NOTE: can cause readability issues with some themes! (eg. white text on white bg)
`uc.tweak.force-tab-colour`
(Left: OFF, Right: ON)

Show context menu navigation buttons (Back, Forward, Reload, etc.) vertically
NOTE: labels are only shown in the English language.
`uc.tweak.vertical-context-navigation`

remove tab separators
`uc.tweak.remove-tab-separators`

use Firefox's default context menu font-size (only applies to Windows)
`uc.tweak.smaller-context-menu-text`

disable custom context menus
`uc.tweak.revert-context-menu`

if a tab's close button is hidden, show it when hovering over tab
`uc.tweak.show-tab-close-button-on-hover`

Mica Tweak Instructions (Windows 11 Only)

Download and install Mica For Everyone.
Create a custom process rule with the following:
1. Name: firefox
2. Titlebar Color: System
3. Backdrop Type: Mica
Enable tweak in about:config: uc.tweak.win11-mica
Restart Firefox.