header, footer{ 
    border-radius: 2em; box-shadow: 10px 10px 10px black;
}

header h1 {
    text-align: center;
}

section{ background-image:url(../imagenes/portada.jpg);
    width: 70%
}
section p{
    text-align: center; color: aliceblue; padding:  2em;
}
header{
    height: 3em; background-image: url(../imagenes/header1.jpg); padding: 3em;
}
nav{
    margin 1em; height: 2em; background-color: gray; text-align: center;
}
nav a{
    margin-right: 2em
}

nav ul{ margin: 0; padding: 0; list-style: none;}
nav li{display: block; float: left; width: 300px; text-align: center; font-size: 20px;}
aside, section{
    height: 400px; float: left; margin-left: 1.5%; margin-right: 1.5%; padding-left: 1%; padding-right: 1%; padding-top: 1em; margin-top: 2em; margin-bottom: 2em; 
}
footer{
    text-align: center; clear: both; background-color: gray; height: 10em;
}
.boton{
    padding: 1%; border-radius: 14px; background-color: azure;
        
}

.correo {float: right; display: block;}

aside{
    text-align: center;width: 20% 
}

body{
    background-color: burlywood;
}

nav li a{display: block; float: left; width: 250px; text-align: center; font-size: 20px; text-decoration: none; color: skyblue}

nav ul li a:hover{
    color: aliceblue;
}

nav ul li.selected a{
    color: aliceblue;
}