From the site:

> I'm fairly familiar with CSS3 and all the new whizz bang CSS things that I could very well use to make this fancy looking, but I decided to go the simplest route. [...] Also it's basically mobile responsive out of the box.

But then I notice some column layout : https://www.andrewjvpowell.com/#about

How is that responsive? Well, "inpect" reveals flexbox, which is very much modern css.

Still minimalist though.