Hello, I am sorry to hear that you dislike the new Proton design; however, I have a similar opinion. I found a program that leverages the new look so that the old (Photon) design looks even better. <i>'''WARNING from the moderator team: This script is not provided by Mozilla and is not officially supported.''' Firefox is a work in progress and, to allow for continuous innovation, Mozilla cannot guarantee future updates won’t impact your customizations. For this reason, Mozilla does not officially support style rules customization. Please read [[Firefox Advanced Customization and Configuration Options]] to learn more. </i> Now that the formalities are out of the way, the place to get the fix is shown below. The tweak requires a change to the userChrome.css file, something that may not work forever. The github repo is black7375/Firefox-UI-Fix