/* all lists */
#nav, #nav ul { padding: 0; margin: 0; list-style: none; line-height: 1; }

#nav a { display: block; width: 4em; }

/* all list items */ /* width needed or else Opera goes nuts */
#nav li { float: left; width: 4em;  }

/* second-level lists */
/* using left instead of display to hide menus because display: none isn't read by screen readers */
#nav li ul { position: absolute; background: orange; width: 4em; left: -999em; }

/* lists nested under hovered list items */
#nav li:hover ul, #nav li.sfhover ul { left: auto;}