Pseudo class selector for element code example
Example: css pseudo classes
button/anchor:hover / :active / :checked
:nth-of-type(3) // select the third element
:nth-of-type(3n) // select an element every three
button/anchor:hover / :active / :checked
:nth-of-type(3) // select the third element
:nth-of-type(3n) // select an element every three