nth-child on Twine 2.0 ?

Hello,
I'm currently writing my first interactive novel thanks to Twine 2.0 (Harlowe), which is a pretty cool thing to do of my evenings.

I tried to stylized a bit my story with a bit of CSS, but I encountered a problem with a CSS option.
I want my links to appear one by one, not in the same time, you know ?

So I tried first to select my 2nd link :

tw-link:nth-child(2){color:red !important;}

But this ins't working, and I don't understand why ! Do you have any idea why ? Maybe you have a solution for me ?

Thank you !
E.