Adding custom CSS to simple CSS as per System Crafters video tutorial

TL;DR Where do I put the CSS stylesheet for my org mode page, and how do I link it to my build.el for an org-mode website ?

I have followed this great tutorial: Build Your Website with Org Mode - System Crafters
And now I have a nice site up and running with simple CSS providing the nice look of the site.
However, I would like to be able to change some things around - like font color, background, bulletpoints etc. - without messing with the responsiveness of the framework provided.

I don’t have much experience with these things, but I before when I have worked with HTML/CSS, the stylesheet.css lived in the website folder, and was evoked with

And since I don’t like being dependent on the external CSS from GitHub - kevquirk/simple.css: Simple.css is a CSS template that allows you to make a good looking website really quickly., I would like to put it somewhere my org site can find it, and also to know where I should put any additional customizations.

Currently my fil-tree for the org-based website, looks like this:
~/websites/org site/ and then in that directory I have content, public, publish.el and the script described in the tutorial.

Can anyone help me with how I go about this?

I finally figured it out :slight_smile:
Didn’t watch that part of the video initially, but have done so now. The thing to do is to download the simple css dir from git, unpack and put simple.css in the /public dir. Then I can change the specs.