nth-child

nth-child.css

/* Select the 2nd child. */
:nth-child(2)

/* Select all even children (2nd, 4th, 6th, 8th, and so on). */
:nth-child(2n)

/* Select all odd children (1st, 3rd, 5th, 7th, and so on). */
:nth-child(2n+1)

/* Select the 1st (=(5×0)+1), 6th (=(5×1)+1), 11th (=(5×2)+1), … child. */
:nth-child(5n+1)

/* Select the 2nd (=(5×0)+2), 7th (=(5×1)+2), 12th (=(5×2)+2), … child. */
:nth-child(5n+2)

/* Select every child from the 3rd one up (3rd, 4th, 5th, and so on). */
:nth-child(n+3)

/* Select every child up to the 5th one (1st, 2nd, 3rd, 4th, 5th). */
:nth-child(-n+5)

/* Select every child from the 3rd one up to the 5th one (3rd, 4th, 5th). */
:nth-child(n+3):nth-child(-n+5)

/* Select the first list item */
li:nth-child(1) { }

/* Select the 5th list item */
li:nth-child(5) { }

/* Select every other list item starting with first */
li:nth-child(odd) { }

/* Select every 3rd list item starting with first */
li:nth-child(3n - 2) { }

/* Select every 3rd list item starting with 2nd */
li:nth-child(3n - 1) { }

/* Select every 3rd child item, as long as it has class "el" */
.el:nth-child(3n) { }