Astra Transparent headers - Design responsive WordPress headers with Free Astra theme and CSS

Wow! This is almost like having the pro version of Astra. Thanks for the CSS

Clear explanation how to make a transparent header.
My question: the explanation starts with a background photo, how do I make a background in astra myself? The background is white by default.

Hi! Is it possible to change the menu font color and hover color using css? Thanks!

how can reduce the site header size?