How to make the menu bar transparent and shift to the picture?

Question

css

I'm tormenting the theme for wordpress NEVE ( https://ru.wordpress.org/themes/neve/ ).
I want to place a menu block with a logo, etc., in the picture and with a transparent background.
I understand that the background color needs to be converted to RGBA and set the degree of transparency from 0 to 1.
But I ran into a difficulty: how to place this panel on the picture, and make the picture fit the screen?

Answer 1

The picture seems to be in the center of the screen.
and the menu can be knocked out of the flow with an absolute and give transparency to the background.
position: absolute
top: 0
left: 0