For Those Who Are Missing Old Looking Firefox
For those who are missing old-looking Firefox like me I have edited default Firefox theme and made it looking like old firefox. All you need to do is download this chrome file and unzip it. After unzipping chrome file place it here on your PC: C:\Users\username\AppData\Roaming\Mozilla\Firefox\Profiles\youprofile.default-release. One more thing to do ope Firefox write about:config to address bar accept next screen click Show all enter open configuration area. Then type toolkit.legacyUserProfileCustomizations.stylesheets and change false to true restart Firefox that's all. Your firefox will be looking like this