Your css is interfering. In userChrome.css or an imported file which contains --url-toolbar-height, replacing it with --urlbar-container-height should fix the problem.

Your css is interfering. In userChrome.css or an imported file which contains --url-toolbar-height, replacing it with --urlbar-container-height should fix the problem.

Thank you! :) But my userChrome.css only has 7 lines and neither of them looks like that:

#nav-bar, #identity-box, #tabbrowser-tabs, #TabsToolbar {

	visibility: collapse;

#nav-bar * {
   visibility: visible !important;

}

How should it look like? Where to put the --urlbar-container-height part? Or maybe Firefox is looking somewhere else for the CSS?

You collapse the Navigation Toolbar, but displays all toolbar items. I'm not sure on what toolbar those items appear. Do you have the menu bar visible as that is the first choice for showing the control buttons? The second choice would be the Tab bar, but you are hiding its tab.

You can use the Browser Toolbox to check out the current rules and see if you can improve things.

• https://firefox-source-docs.mozilla.org/devtools-user/browser_toolbox/

Thank you for the tool - I will check it out, maybe will be able to figure out fix. For the rest, I'm afraid I did not understand much. I haven't change any settings, this seems to be the default for me.

You collapse the Navigation Toolbar, but displays all toolbar items. I'm not sure on what toolbar those items appear.

I assume you refer to the userChrome.css - I did not change anything there, at least not manually. My problem is with url address bar mostly.

Do you have the menu bar visible as that is the first choice for showing the control buttons?

I'm not sure if I understand your question. What menu bar exactly? It should be visible where? I'm attaching screenshot of entire new window, hopefully that could answer any questions.

The second choice would be the Tab bar, but you are hiding its tab.

I have the tab bar visible (or at least I think so ;) )

What theme is that? Try disabling it and see what happens.

What theme is that? Try disabling it and see what happens.

I use the basic theme that comes with Firefox. Tried to change it anyway, but it doesn't seem to have any effect on the problematic UI parts

Does that also happen in [Troubleshoot mode](https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-troubleshoot-mode)?