This is the theme I use on all installations of Firefox that allow it across all my devices. It's beautiful, smoothly animated, and unintrusive.

i like the animation when the Neutron Star affected the Space Time

barra animada, acompaña bien con musica tranquila y ademas se leen bien las opciones y pestañas.. definitivamente mi favorito!

i love this BUT it could even be better if there was a purple version