Google Chrome is themed properly.
Firefox support has been missing since inception as far as I can tell.
This literally makes or breaks my purchase decision as I really really want all my windows to match up properly but I use Firefox.
Please support other web browsers other than Chrome & Edge
thanks in advance
*EDIT* hell if you can add Discord support too I'll make sure everyone I know buys this 
the inconsistency between theming support of different programs is basically why I'm hesitating
obvious applications like Notepad are themed correctly sure but the second the application has any custom titlebar handling it seems like Curtains breaks.
I'm sure the team has considered this but it would be highly appreciated and uniform if you went through some more popular programs and added custom support for them.
Microsoft Suite (word, excel, pp, etc), Adobe Suite (photoshop, animate, after effects, etc), Visual Studio (and Code), Steam, Github Desktop, Razer apps, etc
I would say 90% of the applications I use on a daily basis are unaffected by curtains which is saddening, so if you have any plans in the future to improve compatibility and supported app list, I would love that