Question

It offers built in design files that contain different predefined styles, such as font face, background colour scheme etc.​

Answer 1

This short tutorial is meant for people who want to start using CSS and have never written a CSS style sheet before.

It does not explain much of CSS. It just explains how to create an HTML file, a CSS file and how to make them work together. After that, you can read any of a number of other tutorials to add more features to the HTML and CSS files. Or you can switch to using a dedicated HTML or CSS editor, that helps you set up complex sites.

At the end of the tutorial, you will have made an HTML file that looks like this:

The resulting HTML page, with colors and layout, all done with CSS.

Note that I don't claim th