#nav { height: 40px; width: 790px; }
#main_menu { padding:0; margin:0; list-style:none; background: url(../Images/tab-back.gif) repeat; width: 780px; height:40px; }
#main_menu li { float:left; display:inline; text-align:center;}
#main_menu li a { height:40px; line-height:40px; font-family: Arial, Helvetica, sans-serif; font-size: 13px; font-weight: bold; color: #FFFFFF; text-decoration: none;}
#main_menu li a:hover { text-decoration:underline;}
.spacer { width:20px; }
.small { width:75px; background:url(../Images/tabs75.gif) no-repeat center 0; }
.med { width:95px; background:url(../Images/tabs95.gif) no-repeat center 0; }
.big { width:115px; background:url(../Images/tabs115.gif) no-repeat center 0;}
.language { width:75px; background:url(../Images/tabs75-red.gif) no-repeat center 0;}
.small:hover, .med:hover, .big:hover, .language:hover { background-position:center -40px;}
#cursos, #especimenes, #atta, #memorias, #premios, #unidades, #organizacion, #editorial, #inbioparque, #servicios, #biodiversidadCR, #biodiversidad, #queINBio {
	padding: 0 50px 50px 0;
	visibility: hidden;
	display:block;
	height: 106px;
}

.menu, .submenu, .menuflecha { display:block; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 11px;color:#fff;padding: 0 3px 0 5px;text-decoration: none; line-height: 18px; width: 100%;}
a.menu {background: #6999d3;}
a.menu:hover {background: #a4c9dd;}
a.submenu {background: #3682ba;}
a.submenu:hover {background-color: #a4c9dd;}
a.menuflecha {background: #6999d3 url(../Images/arrow.gif) no-repeat right center;}
a.menuflecha:hover {background:  #A4C9DD url(../Images/arrow2.gif) no-repeat right center; cursor: default;}