Aesthetic bugs

[bphd]

The zone around the close button is darker than the rest of the bar. Between the bar and Tree Style Tab there is a notch meant to round things, but it has a black space between the bar and tree style tab and it's colored like the bar but darker than tree style tab that is blueish. And tree style tab is indeed blueish where the bar is blackish. And folded tree style tab display end of title of tabs rather than favicon and beginning of titles, when it's unfolded it's okay, well, a bit, because hovering a tab makes the favicon fleeing to the left outside the window

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Screenshots
If applicable, add screenshots to help explain your problem.

Firefox Version: