Ability to hide url bar when unfocused
It would be a great option if there was a way to hide the url bar until a user focuses on it by hovering so tabs get maximum space. I know this has been discussed here #20 already but with the theme below I think you could work something out. This theme is sort of what I had in mind. Could you perhaps copy over the relevant css code and tweak it to work with cascade (I have no idea how it works)?
Oh, that actually is really interesting! I think this is made possible by using display: flex; to align everything in one bar. Back when I started this that resulted in some weird behaviour, but the recent updates to Firefox seem to make this possible.
I'll have a closer look at the animated stuff as an alternative version of Cascade for sure, as well as likely refactoring the whole code in favour of flex. ^—^
It's great to see you are still interested in this feature. I think it will make an already great theme even better! :)
In the meantime I actually got an older edit of the CSS that has some of the features – like the buttons sliding on. c: https://gist.github.com/andreasgrafen/52b0936bfb71cd9973d5516c5fa6b55c
I'll check it out.
Any updates?
Sorry for the really late reply, but there actually is an update on this now. The reworked version finally is in a state that makes it close to release. With this there is the ability to set different sizes for the URL Bar based on whether it's focused or not.
Currently those changes can be found on the rework branch.

Better late than never, I thought this project had been abandoned.
Thanks for adding this feature!