Select the last 3 child elements

Question

I know you can select the last child with :last-child or a certain child with :nth-child (if you know their position/number).

What I need is to

Answer 1

You can read more here about nth-last child, but this should basically do the trick of selecting the last 3 children with just CSS

#something a:nth-last-child(-n+3) {
    /*declarations*/
}

fiddle demonstration from Fabrício Matté

This will only select those rows returning a positive number for out N expression (-n+3), and since we are using nth-last-child, it's counting from last to first, so first rows from bottom gives,

f(n) = -n+3
f(1) = -1+3 = 2 <- first row from the bottom
f(2) = -2+3 = 1 <- second row from the bottom
f(3) = -3+3 = 0 <- third row from the bottom

everything else will return a negative number