WordPress. Biztime theme. How to make a transparent background for the header?

Question

css

I work in WordPress , in the Biztime theme . You need to make the background of the header transparent. As you can see in the screenshot, the cap is completely blue , I need it to be transparent , but not too transparent, that is. the background should be clearly visible , but with a slight darkening . Thanks in advance! I hope for your help!

Answer 1

background-color: rgba( r, g, b, a);