My browser just got updated to FireFox Quantum
(Hah, sure thing Mozilla) and let me say for the record that the tabs are UGLY AS f###. Firstly the default was black backgrounds which completely contrasts with the rest of the interface, thankfully easy changed back to light with the tools -> add-on -> themes -> enable light option. Phew! But the tabs themselves are square and ugly with a highlighted color at the top of the current tab - making the entire row look uneven due to lack of uniformity. And the tabs are (naturally) flat, uninspired and completely square. Why are UI designers abandoning rounded edges and pleasing-on-the-eye themes? Has no one seen Star Trek TNG? The LCARS interface is NOT SQUARE! The interface is rounded and one of the most beautiful ever designed (albeit not entirely practical layout, but that's a different matter..).
I blame you Microsoft. You and your square buttons. I still say Windows 7 is the best O/S Microsoft ever put out. I think you'll find that is an absolute fact, and in todays world of 2017, we aren't interested in experts - I think it, therefore it is. A FACT!
Booooo
Edit: This release on github enables curves, albeit a little hard on the eye still:
https://github.com/wilfredwee/photon-australis
The Expanse. Watch it!