Short: 3 different websites using 3 different css techniques.
I took a Udemy-course, Advanced CSS and SASS by Jonas Schmedtmann, and learned more about CSS and SASS, which is used to style a website. By building 3 different websites I also developed my design skills,
and tricks to make things 'pop' like different hover effects and animations.
In the course I built 3 different websites using 3 different techniques.
The first one uses solely float and absolute position to position elements,
the second one focused on flexbox and with the last one I learned how to use the css grid system.
I had a pretty good understanding about float and flexbox but I still learned a lot building these websites.
Now, it's not neccessary to just use one technique when building a website but it was a good way to learn how to use the different techniques.
For example, building this portfolio I used grid to position the individual projects in the projects section on the start page and flexbox pretty much everywhere else.
I didn't build the whole site using grid because the browser support is not as good as flexbox yet,
but a combination of the two techniques makes positioning a lot easier.