CSS known as Cascading Style Sheets was first proposed by Håkon Wium Lie and Bert Bos in 1994. The first official CSS specification, CSS level 1, was released in 1996.
You can find some information and charts about the state of CSS from the last few years.
https://2019.stateofcss.com
https://2020.stateofcss.com
https://2021.stateofcss.com
https://2022.stateofcss.com