FlexFox

A Firefox theme based on VerticalFox, offering enhanced flexibility options.

Previews

Features

• Based on VerticalFox, EdgyArc-fr, Edge-Frfox, ArcWTF, and firefox-csshacks.

• Automatically collapses sidebar, tabs toolbar, and bookmarks toolbar; expands on hover.

• Options to completely hide sidebar, nav-bar, or both for a full-screen-like experience with only web content visible; auto-expands when mouse moves to screen edges.

• Hidden elements expand using an overlap method, preventing content shifting and visual jumps.

• Compatible with menu bar and title bar display; sidebar can be placed on the right side; styles automatically adjust to the chosen configuration.

• Sidebery's Pinned Tabs Bar and Navigation Bar auto-collapse and expand; when expanded, all tabs maintain their positions, eliminating need for mouse repositioning.

• Floating find bar at the top of the screen.

• Compact uni-extensions panel and macOS-style window controls.

Installation

Important

1. Enter about:config in the URL bar and set toolkit.legacyUserProfileCustomizations.stylesheets to "True" to enable custom styles.
2. Install Sidebery.
3. Download the FlexFox package by clicking the link. If you're using Firefox Beta or Nightly (currently versions v133 and v134), please download the Beta version ZIP package instead. For Firefox ESR, use this ZIP package instead.
4. Enter about:support in the URL bar and click Open folder in the Profile folder section to access your profile directory.
5. Copy the chrome folder and user.js file from the Profiles folder in the FlexFox package to your Profile folder, then restart Firefox.
   • After restarting, delete the user.js file you just copied to the Profile folder.
6. Click the gear icon to open Sidebery settings, select Help, then click Import addon data. Import sidebery-settings.json and sidebery-styles.json from the Sidebery folder in the FlexFox package.
   • Sidebery settings may occasionally fail to import properly. If you notice that Sidebery's appearance hasn't changed or the style seems incorrect, please try importing the settings again.
7. In about:config, search for uc.flex and modify FlexFox options as needed.

Options

Preference	Description
uc.flex.add-ui-text-stroke	Bolds Firefox interface text
uc.flex.bookmarks-have-more-margin-left	Increases left margin of bookmarks when placed in nav-bar
uc.flex.hide-sidebery-completely	Fully hides Sidebery
uc.flex.hide-toolbox-completely	Fully hides tabs-toolbar and nav-bar
uc.flex.large-sidebery	Increases expanded Sidebery width
uc.flex.prevent-bookmarks-auto-hide	Disables auto-hiding of bookmarks toolbar
uc.flex.prevent-tabs-toolbar-auto-hide	Disables auto-hiding of tabs-toolbar when Sidebery is disabled
uc.flex.remove-bookmarks-folder-icons	Removes bookmark folder icons
uc.flex.remove-bookmarks-labels	Removes bookmark labels
uc.flex.restore-uni-extensions-panel	Disables compact uni-extensions panel, switching to condensed uni-extensions panel
uc.flex.restore-window-controls	Disables macOS-style window controls, reverting to default controls
uc.flex.sidebery-hover-fast-expand	Speeds up Sidebery's expand/collapse on hover
uc.flex.sidebery-hover-slow-expand	Slows down Sidebery's expand/collapse on hover

Known Issues

If you're using the Floorp browser, please select the Firefox Proton UI in Floorp's interface settings to minimize styling compatibility issues.

This style has only been tested on Windows. Manual adjustments may be needed for other operating systems.