The CSS pseudo-class selectors are selectors that are based on some other attribute beyond the element's name, attributes or content. The pseudo-class selectors are:
- :active matches on active links.
- :first-child matches on the first child of the element.
- :focus matches when the element has focus.
- :hover matches when the element is hovered over by the mouse.
- :lang matches on the language of the document.
- :link matches unvisited links.
- :visited matches visited links.
To remove the underlines from links once they have been visited:
a:visited {
text-decoration : none ;
}
Or to match the first child element of a div, no matter what element it was:
div:first-child {
border : 1px solid blue ;
}

