anchor.diff:              text = profile.userChrome;
             };
   
  +        "${profilesPath}/${profile.path}/chrome/userContent.css" =
  +          mkIf (profile.userContent != "") {
  +            text = profile.userContent;
  +          };
  +
           "${profilesPath}/${profile.path}/user.js" =
             mkIf (profile.settings != {} || profile.extraConfig != "") {
               text = mkUserJs profile.settings profile.extraConfig;
  
positive.code:                     visibility: collapse !important;
                    }
                  }
                '';
              };
  
  
negative.code:             userChrome = mkOption {
                type = types.lines;
                default = "";
                description = "Custom Firefox user chrome CSS.";
                example = ''
                  /* Hide tab bar in FF Quantum */
                  @-moz-document url("chrome://browser/content/browser.xul") {
  