This page is made up of pure HTML. There is nothing else going on. No CSS, no Java Script, nothing.
I made this page to show you that you do not need a stylesheet to make your website functional. What you are seeing is what your browser has "decided" to show you. The font, font sizes, and spaces between paragraphs and letters are all determined by the browser and operating system you are using.
Is this pretty? Well, I would say no. But beauty lies in the eye of the beholder anyway, so don't listen to me.
What's important is that it is functional.
Hmmm... I think it would be fun to make a stye toggle, so that visitors can choose if they want to view the styled (pretty and colourful) or unstyled (pure HTML) version of my site.