html,body{margin:0; padding: 0;height: 100%}

div#contenitore {
    width: 900px;
    margin-left: auto ;
    margin-right: auto ;
}

div#titolo {
    height: 150px;
    background-color: #ffffff;
}

div#menu{
    float: left;
    width: 13em;
    }
    
div#contenuto{
    background: linear-gradient(rgba(255,255,255,.5), rgba(255,255,255,.5)), url("PietroTR.gif");
    margin-left: 13em;
    padding: 20px;
    background-repeat: no-repeat;
    background-size: 100%;
    min-height: 1000px;

    }

   
li {
 outline: none;
 cursor: pointer;
 text-align: center;
 text-decoration: none;
 font: bold 14px Arial, Helvetica, sans-serif;
 color: #fff;
 padding: 10px 20px;
 border: solid 1px #DF750F;
 background: #DF750F;
 margin:15px;
 -moz-border-radius: 8px;
 -webkit-border-radius: 8px;
 border-radius: 8px;
}

ul {
    display: block;
    padding: 5px;
}