I closed that thread because that thread is about placing the tabs in the lower position and that issue has been solved. Your question is about extra appearance features that aren't covered by the thread subject. You posted a very long CSS file from Aris that is hardly workable for us to spit out what needs to be changed or added. Best would be to ask at FirefoxCSS subreddit or to contact Aris for support to find out what needs to be done. *https://www.reddit.com/r/FirefoxCSS/