I first started enjoying doodling with valid HTML & CSS in 1998.
Between 2001 and 2011 I designed over 50 websites, many of which are no longer online.
In 2018 I restarted designing, creating and helping small sites to improve their web appearance, particularly appropriate color and they validate.
Here is a few of the many: 20 Years of Web Design.
I utilise many websites for writing/creating CSS, HTML, HTML5, graphics, and many more related subjects - and publish them on my blog or my brainfeed.