FirefoxCSS-Store VS CustomJSforFx

search for it on https://firefoxcss-store.github.io/ if you need assistance go to r/FirefoxCSS

yes, we can put "links of interest" on the web to collect all the communities, websites, or whatever related to firefox themes.

You can also remove that unnecessarily large sidebar header that Firefox insists on not letting users disable via normal means with userchrome mods. Some such setups can be seen at https://firefoxcss-store.github.io/.

firefox's ui is very customizable with css and i dont see why flatpak would change that. here are some examples https://firefoxcss-store.github.io/

I like to use this

If somehow this could be integrated with the css store down the line, I can see a lot more casual Firefox users finally trying out css customisations.

you can find others here https://firefoxcss-store.github.io/

You might want to take a look at Firefox CSS. There are some themes for home page and at the end of the site is guide: https://firefoxcss-store.github.io/

There's also this script.

it's a free country software, the only limit to modification is your own good sense. This repo has a ready made user script to move the address to the tab bar like in your sceenshot. https://github.com/Aris-t2/CustomJSforFx/wiki

Are other userChrome.js working? Please test. A red restart button will appear on the toolbar. https://github.com/Aris-t2/CustomJSforFx/blob/master/scripts/restart_button.uc.js

I have an additional toolbar created by the script by Aris (https://github.com/Aris-t2/CustomJSforFx/blob/master/scripts/additional_top_toolbars.uc.js)

According to the javascript here (https://github.com/Aris-t2/CustomJSforFx/blob/master/scripts/additional_top_toolbars.uc.js) the first additional toolbar appears to have the ID #additional_top_toolbar1, the second #additional_top_toolbar2, and so on. I only need to work with #additional_top_toolbar1, and switch it with the navigation toolbar.

if you want a favicon in the urlbar you'll need to use a script. fortunately there is already a script for this. I don't use it myself but I think it should work.