@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

#star-button-box { display:none!important; }

You can no longer remove the star from the location bar via the right-click context menu or via customize mode in 89+. You now need to use code in userChrome.css to hide the star. Add code to the <b>userChrome.css</b> file below the default @namespace line. <hr> <pre><nowiki>@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */ #star-button-box { display:none!important; } </nowiki></pre><hr> *https://www.userchrome.org/what-is-userchrome-css.html *https://www.userchrome.org/how-create-userchrome-css.html In Firefox 69 and later you need to set this pref to true on the <b>about:config</b> page to enable userChrome.css and userContent.css in the chrome folder. *toolkit.legacyUserProfileCustomizations.stylesheets = true *https://www.userchrome.org/firefox-changes-userchrome-css.html