With today's Firefox update, the edges of the tabs, that allow me to visually distinguish between the multiple tabs that I always have open, disappeared. Now, it is only the font/text that is visible when looking at my browser's multiple tabs. The edges have disappeared, only showing up as a faint shadow when I hover the pointer over a tab. And depending on the name listed on the tab, this makes it very difficult to distinguish one tab from another. This change to the way that Firefox looks is making it difficult for me to maneuver between tabs, and get my work done. I tried changing colours, as well as the different themes, but in all cases, the edges remain invisible. Attached is a screen image of the different colour/themes, showing that in every case, the edges of the tabs remain invisible. Is there a way to bring the edges back into view? Thank you in advance for your assistance.