The easiest way to prove that CSS is not Turing complete is to demonstrate that every CSS "program" terminates, therefore halting problem is solvable for CSS. I

The easiest way to prove that CSS is not Turing complete is to demonstrate that every CSS "program" terminates, therefore halting problem is solvable for CSS. Indeed, a proper CSS engine will process a set of CSS rules in finite time, or display an error. Therefore CSS cannot be Turing complete.