Solution found.

That would be something like this:

#tabbrowser-tabs .tab-text{
 font-size:12pt !important;
 font-weight: bold !important;
}

Ref: Tab's Default Font Size?

cor-el said

That would be something like this:

#tabbrowser-tabs .tab-text{
 font-size:12pt !important;
 font-weight: bold !important;
}

What is the default size?

~Pj

This will be a solution once someone tells me where it is I need to change the text.

It is not that difficult to create userChrome.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.

• https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox

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 text file with the name userChrome.css (name is case sensitive). In this userChrome.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 userChrome.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 and restart Firefox when you create or modify the userChrome.css file.

Thank you for your detailed insrtructions. Much appreciated. I guess I should have told you I do not use a PC. My computer is an iMac. Sorry for not mentioning this.

Hi Helen.of.Joy, the procedures for creating a userChrome.css file on Mac are not much different than for Windows. See: https://www.userchrome.org/how-create-userchrome-css.html

Thank you.

Thanks to all who helped me understand how to insert code into a chrome.css file. I have an additional question. Could someone please give me the code to increase the font size of the BOOKMARKS TOOL BAR items?

Hi Helen.of.Joy, for the Bookmarks Toolbar, take a look at the code in this thread:

firefox 65 how do I edit css for toolbar fonts

THANKS AGAIN!