Vince

That's the separators,

@soonshiny Thank you for your solution, Firefox's support for gtk3 themes are not good, These problems have been kept for a long time, and I really don't have good way...

I'll fix this

No problem

I'll change that

If I get time, I will try to add openbox and lxde theme

OK, thanks, I'll mention that

我检查一下看是不是代码有问题

I don't have this problem, are you sure this theme make cpu getting utilized average 50%?

Could you tell me your system and desktop version, also you can use gnome-tweaks to show me your font set