html{
    /*width:1400px;*/
    font-size:16px;
}
body{
    margin:0;
    width:100%;
}
nav{
    border-radius: 10px;
    background-color: rgb(185, 208, 245);
    width: 30%;
    margin: 0 auto;
    text-align: center;
}
h1,h2,h3{
    text-align: center;
}
nav a{
    display:inline-block;
    padding: 0.5%;
    border-radius: 4px;
    background-color: rgba(240, 248, 255, 0.534);
    margin: 1em 3% 1em 6%;
}
nav a:hover{
    cursor: grab;
    transition: 0.5s;
    padding: 0.7%;
}
form{
    margin:auto;
    border-radius: 10px;
    width: 40%;
    background-color: rgb(185, 208, 245);
    padding: 2%;
}
input[type="submit"]{
    margin: 3em 0 0 30%;
    padding: 1%;
    font-weight: bolder;
    font-style: italic;
    font-size: large;
    box-shadow: rgb(149, 131, 108) -3px 3px 5px;
}
input[type="submit"]:hover{
    cursor: grab;
    transition: 0.5s;
    padding: 1.5%;
}
select{
    margin: 0 0 1em 10%;
}
label{
    margin: 0 0 1em 10%;
}
#textoEmpujado{
    margin: 0 0 0.5em 27%;
}
#desplegableCursos{
    margin:1em 0 1em 40%;
    border-radius:10px;
    border:0;
    background-color:rgba(240, 248, 255, 0.534);
    font-size: 1.5em;
    padding:1%;
}
#desplegableCursos:hover{
    transition: 0.5s;
    cursor:grab;
    background-color:rgb(240, 248, 255);
    font-size: 1.6em;
    padding:1.1%;
}
#desplegableCursos:focus{/* focus es el elemento que tienes seleccionado */
    transition:0;
    background-color:rgb(255, 255, 255);
}