h2.nivel_2::first-letter{
    font-size: 40px;
}

.sangrado{
    text-indent: 2em;
}

a::before{
    content: "→";
}

abbr:after{
    content: "(" attr(title)")";
    font-style: italic;
}


.regresar{
    margin-top: 250px;
    text-align: center;
    font-size: 25px;}
    .back{
        font-family: Verdana, Geneva, Tahoma, sans-serif;
        text-decoration: none;
        color: black;}
        .back:hover{
            text-decoration: underline;
}