HELP with login background

Hi need some help to make the background black + adding site logo back in
- screenshot changes -
- link -

I added this

body.login {
background-color: #000;

to the file
and functions.php in child theme -

purged wodpress side. but seems to have no effect?

Support Access is open for the next 5 days.

Please dont post any brand related information/ screenshots or domain links as i have had issues with google caching this information and linking it to their google searches of my site ... very bad for brand... please use temporary image upload / tiny url / pastebin etc to mask this information.