How to select a range of elements in repeated pattern

This is a commonly-asked question, but I wanted to point out that the reason :nth-child(n+4):nth-child(-n+6) only matches one specific range of elements is that it only provides a single start point (n+4) and a single end point (-n+6). The only elements that can be greater than or equal to 4 and less than or equal to 6 are 4, 5 and 6, so it’s impossible to match elements outside of this range using the same selector. Adding more :nth-child() pseudos will only narrow down the matches.

The solution is to think of this in terms of columns, assuming there will always be exactly 3 columns (elements) per row. You have three columns, so you will need three separate :nth-child() pseudos. Elements 4 and 10 from the first column are 6 elements apart, so the argument to all of the :nth-child() pseudos needs to start with 6n.

The +b portion in the An+B expression can either be +4, +5 and +6, or 0, -1 and -2 — they will both match the same set of elements:

  • li:nth-child(6n+4), li:nth-child(6n+5), li:nth-child(6n+6)
  • li:nth-child(6n), li:nth-child(6n-1), li:nth-child(6n-2)

You cannot do this with a single :nth-child() pseudo-class, or a single compound selector consisting of any combination of :nth-child() pseudos, because the An+B notation simply doesn’t allow such expressions to be constructed that match elements in ranges as described.

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