I've noticed that the line-numbers are defined twice and that's not necessary. Additionally I have tweaked the tab-line a bit:
Active tab looks like buffer, while others look like the fringe.
Move the tab-line resizing outside the theme. There might be people who are happy with the default size settings for the tab-line (not my case, but I do that after loading the theme).
HI
I've noticed that the line-numbers are defined twice and that's not necessary. Additionally I have tweaked the tab-line a bit: