title: CSS nth-child: what exactly does nth-child(1n) select
body: <p>I have been reading this <a href="https://css-tricks.com/how-nth-child-works/" rel="nofollow noreferrer">article</a> and it is pretty clear to me so far that something along the lines of: <code>ul li:nth-child(3n+3)</code> will select every 3rd <code>li</code> due to the fact that the &quot;n&quot; within the expression starts at zero and then represents a set of all positive integers; so n = 0, n = 1, n = 2, etc., which in the article I have linked goes on to indicate that indeed <code>:nth-child(3n+3)</code> is tantamount to (3x0)+3 which equals 3, (3x1)+3 equals 6 and so on. I have also seen similar CSS such as: <code>.some-selector:nth-child(1n); .some-selector:nth-child(2n); </code>
  What I glean from the examples from the aforementioned article leads me to posit that <code>.some-selector:nth-child(1n);</code> would equate to <code>.some-selector:nth-child(0);</code> but this also feels wrong to me. Can someone help me to better understand this? Thanks</p>