body {
    color: #1e48a7;
}

#ivideo{
    width: 420px;
    height: 315px;
    float: left;
}

#desc_style:after {content: "Estilo ancho";}
    
#main section #titulo {
    margin-left: 30px;
}
nav span  { margin: 0px 200px 0px 0px;}
    
header {
    background-color: #1e48a7;
    color: #0defdd;
    font-size: 40px;
}
    
header, nav, section, header, article, footer {
    border: 4px solid #1e48a7;
}