Hi. I've been using Firefox 52-56 for a really long time. I have not yet made the switch to Firefox 66.0.5, but I am trying to. There are so many limitations in Quantum, and it is really hard to ignore them. i.e. - I can't set Firefox to open the Downloads (Library) window with F3 because you can't create a shortcut for the Downloads window and you will also open up Find Again if you press F3. But I'm trying. And I think I am making some progress. I had to install Linux for the first time in my life and edit the Firefox binary omni.ja. Oh what joy! So anyway, I ran into a new problem. The Downloads (Library) window. It used to have the 'Clear Download's button on the top left side. It's so strange to have moved it to the right side, when there is no advantage. I mean it is actually a big disadvantage to move it to the right side, and very inconsistent. If you click History, the search bar is flush on the right side. If you click Bookmarks, the search bar is flush on the right side. But if you click Downloads now, the search bar is no longer flush on the right side because of the search bar. Not only that, but it's been a lot more intuitive, faster, and easier to click that 'Clear Downloads' button when it was on the left side. Now, I'm always looking for it, always dragging my mouse long distances, losing more time, making more effort, experiencing more headache... I've been playing a lot with userChrome.css code, and I learned how to use the Browser Toolbox. But it's not letting me see, highlight, or select any elements in the Library window. What can I do? I just want to move the 'Clear Downloads' button the left WHERE IS BELONGS.

/* LIBRARY: move #clearDownloadsButton to the left */
#placesToolbar #libraryToolbarSpacer { -moz-box-ordinal-group: 3 }
#placesToolbar #searchFilter { -moz-box-ordinal-group: 4 }
#placesToolbar #clearDownloadsButton { -moz-box-ordinal-group: 2 }