body {
	background: #FFFFFF url('images/fondo1.gif') center top repeat-y;
	height: 100%;
	text-align: center;
	font-family: Verdana, Arial;
	margin: 30px;
	}
	
#centrador {
	background-color: #FFFFFF;
	width: 720px;
	height: 683px;
	margin: 0 auto 0 auto;
	text-align:left;
	}

.base {
	background-color: #FFFFFF;
	position: absolute;
	z-index:1;
	margin: 0 0 30px 0;
    height: 683px;
	width: 720px;
	}

.top {
	position: absolute;
	margin: 10px 10px 0px 10px;
	z-index:9;
	width: 700px;
	height: 170px;
	}
	
.subtop {
	position: absolute;
	z-index: 100;
	margin: 188px 0px 0px 10px;
	width: 510px;
	height: 30px;
	border-bottom:3px solid #DEDEDD;
	}

.columna {
	background-color: #FFFFE5;
	position: absolute;
	margin: 188px 0 0 530px;
	z-index:9;
	text-align: center;
	width: 180px;
	height: 485px;
	color: #000000;
	background-color: #DEDEDD;
	}

.contenido {
	background: #FFFFFF url('images/contenido-fondo.jpg') left bottom no-repeat;
	z-index:1;
	background-attachment: fixed;
	position: absolute;
	margin: 220px 10px 0px 10px;
	width: 510px;
	height: 453px;
	color: #000000;
	font-family: verdana, arial;
	font-size: 10px;
	overflow: auto;
	overflow-x: hidden;
	}

.columnamedio {
	background: #FFFFFF url('images/columna-separador.gif') center center no-repeat;
	position: relative;
	overflow: auto;
	overflow-x: hidden;
	width: 160px;
	height: 205px;
	color: #000000;
	padding: 20px 10px 10px 10px;
	font-family: verdana, arial;
	font-size: 10px;
	background-color: #DEDEDD;
	}

.columnabottom {
	position: relative;
	width: 180px;
	height: 50px;
	}

a:link {
	text-decoration: none;
	color: #E65200
 	}
	
a:visited {
	text-decoration: none;
	color: #E65200
 	}
.style6 {font-size: 9px}
.style9 {font-size: 9px; font-weight: bold; color: #666666;}
.style8 {
	font-size: 16px;
	font-weight: bold;
}

.nav, .nav ul { 
	list-style: none;
	margin: 0;
	padding: 0;
}

.nav {
  font-family: verdana;
  position: relative;
  width:510px;
  height: 30px;
}
.nav li {
  border-left: 3px solid #DEDEDD;
  float: left;
  margin: 0;
  padding: 0;
  position: relative;
}
.nav li a, .nav li a:link, .nav li a:active, .nav li a:visited {
  background: #FFFFFF;
  color: #000000;
  display: block;
  padding: 5px 5px 5px 5px;
  text-decoration: none;
}

.nav li a:hover {
  background: #ccc;
  color: #000000;	

}
#nav-one li:hover a, 
#nav-one li.sfHover a {
  background: #ccc;
  color: #000;
}
#nav-one li:hover ul a, 
#nav-one li.sfHover ul a {
  background-color:#DEDEDD;
  color: #000000;	
}
#nav-one li:hover ul a:hover, 
#nav-one li.sfHover ul a:hover {
  background: #FFFFFF;
  color: #000;	
}

.nav ul {
  list-style: none;
  margin: 0;
  position: absolute;
  top: -999em;
  left: -1px;
}
.nav li:hover ul,
.nav li.sfHover ul {
  top: 27px;
}
.nav ul li {
  border: 0;
  float: none;
}
.nav ul a {
  border: 1px solid #FFFFFF;
  border-bottom: 1px solid;
  margin: auto auto auto 0px;
  padding: 20px 20px 20px 20px;
  width: 150px;
  font: verdana;
}
.nav ul a:hover {
  background: #ccc;
  color: #000000;
}
    .style11 {
	font-size: 14px;
	font-weight: bold;
}
    .style12 {
	color: #000000;
	font-size: 9px;
	font-weight: bold;
}
<!-- RECORDATORIO: El orden de control de margenes es: Arriba Derecha Abajo Izquierda -->