.contenedor_descargas
{
    width: 100%;
    height: 28em;
    text-align: center;
    padding-top: 4em;
    margin-top: -1em;
}

.contenedor_descargas a
{
    background: transparent url("/img/descarga.png") no-repeat center top;
    padding: 250px 20px 0;
    height: 40px;
    display: inline-block;
    font-size: 1.2em;
    font-weight: bold;
}

.contenedor_descargas a:hover
{
    box-shadow: 0 0 1px 0 rgba(0, 0, 0, 0.5);
}