a:link  { color: blue; }
a:active { color: red; }
a:visited { color: purple; }
a:hover  { color: red; }
a.nav   { font-weight: bold; text-decoration: none; }
a.nav:hover, a.nav: active { background-color: yellow; color: red; }
a.nav:link, a.nav:visited { color: green; }
