.mypets{ /*header of 1st demo*/
cursor: hand;
cursor: pointer;
border: 0px solid gray;

}

.openpet{ /*class added to contents of 1st demo when they are open*/
background:;
}

.technology{ /*header of 2nd demo*/
cursor: hand;
cursor: pointer;
font: bold 14px Verdana;
margin: 10px 0;
}


.openlanguage{ /*class added to contents of 2nd demo when they are open*/
color: green;
}

.closedlanguage{ /*class added to contents of 2nd demo when they are closed*/
color: red;
}
.mypets1 {cursor: hand;
cursor: pointer;
border: 0px solid gray;
background: #666666;
}

.mypets2 {cursor: hand;
cursor: pointer;
border: 0px solid gray;
background: #666666;
}
.mypets3 {cursor: hand;
cursor: pointer;
border: 0px solid gray;
background: #666666;
}
<style type="text/css">

.Estilo1 {color: #000000}
.Estilo10 {font-size: 16px}
.Estilo11 {color: #000000}
.Estilo12 {
	color: #666666
}
.Estilo13 {color: #FFFFFF}
.EventoPrincipal {
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 16px;
}
.EventoPrincipalTexto {
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 12px;
}