How i can create or change color fond of this line please ?

[scorpss]

hello dear support ,

i want to know where i can make this line more black fond? look at this forum , i want the sime :



here is my forum :



how I can darken the line and have a big black line?

[Iain M]

Edit the forumbits_border StyleVar

[scorpss]

thank you alot ! !