You need unbounded recursion. Conditionals alone can’t do that. If you have some kind of conditional go to/jump if expression that’s a different matter.

You can emulate recursion with iteration and a push-down stack. If it doesn’t either recurse or offer both iterations (loops) and something that can act as a stack (at least an array or so) then it’s not Turing complete though. I have yet to see a stack or user-manipulable arrays in CSS.

You can't add all possible conditionals for every kind of loop/iteration, such as dynamic and infinite.