I have a real distaste for this question. It might seem like a fun question to dig into on the surface, but the way it enters public discourse rarely seems to be in good faith. There are ulterior motives at play involving respect, protective emotions, and desires to break or maintain the status quo.
If someone can somehow prove that CSS isn’t a programming language (this is such a gray area that if that was your goal, it wouldn’t be terribly hard to do) then they get to keep on feeling superior in their “real” programming skills and rationalize the fact that they are (likely) paid more than a front-of-the-front-ender specializing in CSS. This is maintaining the status quo.
The reverse can also be true. If you can prove that CSS is a programming language, perhaps you can shift your own company or the industry at large toward equal respect and pay toward front-of-the-front-end developers. This is breaking the status quo.
Let’s say we could all agree on a boolean true or false on if CSS is a programming language. What now? If true, is pay normalized among all web workers? If false, do CSS specialists deserve pay cuts? If true, does everyone start respecting each other in a way they don’t now? If false, do CSS people have to eat lunch in the boiler room? I have doubts that anything will change; hence my distaste for the discussion at all.
> node my-program.js
Sure as eggs is eggs, that program will execute. You can make “Hello, World!” print to the terminal with console.log(“Hello, World!”);.