Firefox Hide native tab bar if Sidebery is enabled

userChrome.css

/*
This is a userChrome for Firefox
that hides the native tab bar,
but only if the Sidebery bar is enabled.

Instructions:

1. Enable loading of userChrome in Firefox:
    1.1 Go to about:config
    1.2 Search for toolkit.legacyUserProfileCustomizations.stylesheets
    1.3 Set it to true
2. Configure Sidebery to use the preface
    2.1 Go to Sidebery settings
    2.2 Go to help
    2.3 Set *Preface value* to "sidebery"
        and enable *Add preface to the browser window's title*
3. Install the custom style
    3.1 In the Firefox menu, go to Help > More Troubleshooting Information
    3.2 Search for *Profile Folder* on the page, and open that directory
    3.3 Inside the Profile Folder, create a "chrome" directory if it doesn't exist
    3.4 Inside the chrome directory, create a "userChrome.css" file if it doesn't exist
    3.5 Copy the contents below to userChrome.css
4. Restart Firefox

Related links:
- https://github.com/mbnuqw/sidebery
*/

#main-window[titlepreface*="sidebery"] #TabsToolbar {
  display: none;
}