Space between header and body

Hello!

I am building a website with WordPress. It is running locally using MAMP until ready for upload, therefore no link available, sorry

I’ve started the work 2 weeks ago with the then current WordPress version 5 and twenty nineteen as theme.

I’ve tweaked the theme visually to mostly great success, but would like to do another tweak that I cannot pull off.

So, it is regarding the whitespace between header and body. I have a space of 460 pixels between header and body title on every page of my site on a 1080p display. I’d like it to be way less, maybe a 1/3rd or so.

Which css setting is this in which css file? I could not find anything appropriate in style.css but might have overlooked it.

Thanks

P.S. I did not know where to post this, I cannot post in Themes for some reason.