Thank you, Kovid.
After quite a bit of time debugging, I finally managed to adjust letter-spacing. Although it behaves very strangely, for example:
Code:
.s { letter-spacing: 1 }
does nothing, but:
Code:
.s1 { letter-spacing: 1 }
sets spacing for classes 's' and 's1' to 's10', although:
Code:
.s2 { letter-spacing: 1 }
does not affect anything but 's2'.
Unfortunately, 'normal' or '0' produces too condensed text, and '1' or '0.1em' too much expanded, and '0.5' or '0.05em' get rounded to '0' and '0.6' to '1'