CSS isn't a programming language but..

[LukyVj]

You could easily make an "Hello world" in CSS using pseudo-element and a pseudo class ( :before/:after ) using the "content" property. Like so:

.element:after { 
  content: "Hello world"
}

[RemasteredArch]

Using body as the selector would make it work without needing to add HTML.

body::after {
  content: 'Hello World!'
}

[LukyVj]

Indeed!

[AnshuWorld]

i want to contribute here please assign me

[ad-si]

@AnshuWorld Feel free to open a Pull Request. I'd happily review it =)