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Changing browser styles

  • 2 replies
  • 1 has this problem
  • 9 views
  • Last reply by JBPressac

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Hello, Firefox highlights the <mark> HTML tags. Is there a way to disable this highlight, for instance by modifying the browser styles ? Thank you

Chosen solution

See:

The CSS rules for mark are defined in this file.

  • resource://gre-resources/html.css
mark {
  background: yellow;
  color: black;
}

--- You can add code to the userContent.css file.


/* reverse CSS code for mark element */
mark {
  background: unset !important;
  color: unset !important;
}

It is not that difficult to create userContent.css if you have never used it.

The first step is to open the "Help -> Troubleshooting Information" page and find the button to access the profile folder.

You can find this button under the "Application Basics" section as "Profile Folder -> Open Folder".
If you click this button then you open the profile folder in the Windows File Explorer.
You need to create a folder with the name chrome in this folder (name is all lowercase).
In the chrome folder you need to create a plain text file with the name userContent.css (name is case sensitive).
In this userContent.css text file you paste the text posted.

In Windows saving the file is usually the only time things get more complicated because Windows can silently add a .txt file extension and you end up with a file named userContent.css.txt.
To avoid this you need to make sure to select "All files" in the dialog to save the file in the text editor using "Save File as".

You need to close (Quit/Exit) and restart Firefox when you create or modify the userContent.css file.

See also:

In Firefox 69 and later you need to set this pref to true on the about:config page to enable userChrome.css and userContent.css in the chrome folder.

  • toolkit.legacyUserProfileCustomizations.stylesheets = true

See:

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Chosen Solution

See:

The CSS rules for mark are defined in this file.

  • resource://gre-resources/html.css
mark {
  background: yellow;
  color: black;
}

--- You can add code to the userContent.css file.


/* reverse CSS code for mark element */
mark {
  background: unset !important;
  color: unset !important;
}

It is not that difficult to create userContent.css if you have never used it.

The first step is to open the "Help -> Troubleshooting Information" page and find the button to access the profile folder.

You can find this button under the "Application Basics" section as "Profile Folder -> Open Folder".
If you click this button then you open the profile folder in the Windows File Explorer.
You need to create a folder with the name chrome in this folder (name is all lowercase).
In the chrome folder you need to create a plain text file with the name userContent.css (name is case sensitive).
In this userContent.css text file you paste the text posted.

In Windows saving the file is usually the only time things get more complicated because Windows can silently add a .txt file extension and you end up with a file named userContent.css.txt.
To avoid this you need to make sure to select "All files" in the dialog to save the file in the text editor using "Save File as".

You need to close (Quit/Exit) and restart Firefox when you create or modify the userContent.css file.

See also:

In Firefox 69 and later you need to set this pref to true on the about:config page to enable userChrome.css and userContent.css in the chrome folder.

  • toolkit.legacyUserProfileCustomizations.stylesheets = true

See:

Helpful?

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Thank you very much for this detailed answer.

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