http://3oamv2de6ooacy72hv3ulym3i3vvlprlkqas7hhzo4pu5nyxnji37zad.onion/blogs/writing-a-website-part-2
The purpose of CSS is to change the look and feel of the web page, but as you learn more about it, you might get tempted to ignore the HTML structure completly, we will try to avoid that here. CSS is not just for styling HTML, it can be used to style SVG or XML documents, and some graphical user interface toolkits also supports styling via CSS, so it is always good to learn a bit about it.