Hello, Yes, I also was surprised when I updated this morning to version 89 and found the ui different. After using it the entire day I still don´t feel the habituation effect settling in. Unfortunately, it is rather the contrary. Having read this thread: https://support.mozilla.org/en-US/questions/1338016 thanks to Jscher2000 I was able to revert the ui to the old appearance, but since this appears to be only a temporary solution, I would really appreciate if Mozilla would allow users to have a choice between the old and the new style beyond version 90. And since I said "old", the design before 89 is certainly not that; it simply provides a way better visibility than the design introduced in 89, while being modern in appearance and convenient to look at. Be better than Microsoft; don´t change things for the sake of change, please.