How to Customize Firefox Quantum’s New Interface

Firefox Quantum is here, and it’s chock full of improvements, including the new Photon UI. Photon replaces the “Australis” interface that’s been used since 2014, and features a ton of customization options. Which is good, because there are a few annoyances—like all that empty space on either side of the URL bar.
by Dennis Stewart via How-To Geek