I have learned these over the years, plus a couple of years ago, I took a Web Development Class to learn more.
I learned how to code websites with HTML, CSS3, and some Javascript. I also know a little bit of everything else from CSharp, Python, and some C++ (even though its been a long time).
Yes, I have studied CSS3 for quiet a while now. I even took a Web Development Class to study some more of it, and to refresh my memory on how well I can design websites with it.
Even though that Javascript, at least for me, is still harder to learn and to memorise, but I still know some knowledge of Javascript.
Some of the projects I have done over the years.