@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Serif:wght@200&display=swap'); 

*{ padding: 0; margin: 0; box-sizing: border-box; transition: 1s all; }

a:hover {
    box-shadow: 0.2rem 0.2rem 0.2rem #220095; 
    padding: 1%; 

}

<!-- portada -->

nav { 
    color: #ffffff; 
    background:rgba(0, 0, 0, 0.85);
    font-family: 'IBM Plex Serif', serif;
    padding: 0.5rem;
    text-align: center;
    margin:-2rem 0rem 0rem 0rem;
    
}

nav ul li { 
    display: inline-block; 
}

nav ul li a { 
    color: #ffffff; 
    text-decoration: none;  
    margin: 5rem; 
}

header { 
    color: #ffffff; 
    background-image: url(../img/portada.jpg); 
    padding: 2rem 0rem 4rem 0rem; 
    text-align: end;
    background-repeat: no-repeat;
    background-size: cover;
    width: auto;
    background-position: center;
}

.titulo{
    font-family: 'IBM Plex Serif', serif;
    font-weight: 500; 
    font-size: 500%; 
    padding: 2rem 0rem -5rem 0rem; 
}


main section { 
    text-align: center;
}

    
.inicio {
    display: flex; 
    justify-content: space-between;
}

.integrantes {
    color: #fff;
    font-family: 'IBM Plex Serif', serif;
    font-weight: 700;
    font-size:200%;
    margin:1rem 0 2rem 0;
}

.section-fotos{
    padding-top: 1rem;
    background: #000000; 
}

.fotos { 
    padding: 0 3rem 2rem; 
    width: 100%; 
    border-radius: 6rem;
    display:flex; 
    justify-content: space-between; 
    flex-flow: wrap; 
    align-self: center;
}
 
.cuadro { 
    width: 20%; 
    padding: 0.8rem; 
    display: flex; 
    flex-flow: column; 
}

.cuadro .foto {
    width: 6.25rem; 
    height: 6.25rem;
}
    
.contenido { 
    font-family: 'IBM Plex Serif', serif;
    font-weight: 400; 
    font-size: 1rem; 
    text-decoration: none; 
    padding: 0.5rem; 
    display: inline-block; 
    text-align: center;
}


.foto { 
    width:5rem; 
    height:5rem; 
    border-radius:10px;  
    align-self: center;
}

.columna1 { 
    color: #fff;
    background:#000000; 
    font-family: 'IBM Plex Serif', serif;
    width: 100%; 
    padding: 2rem 2rem 3rem 2rem; 
    border-top: 0.1rem solid #a0a0a0;
    border-bottom: 0.1rem solid #a0a0a0;
    
}

.columna2 { 
    color: #fff;
    background:#000000; 
    font-family: 'IBM Plex Serif', serif;
    width: 100%; 
    padding: 2.2rem 2rem 3rem 8rem;
    border-top: 0.1rem solid #a0a0a0;
    border-bottom: 0.1rem solid #a0a0a0;
}


footer { 
    color: #ffffff; 
    background: #000000;
    padding: 1rem; 
    font-size: 0.8rem; 
}


.plan { 
    font-family: 'IBM Plex Serif', serif;
    font-weight: 800; 
    font-size: 1rem; 
    text-decoration: none; 
    padding: 2.2rem 40rem 10rem 2rem; 
    display: inline-block; 
    text-align:left;
}

.map {
    background-color: #f2f2f2;
}
.mapa {
    padding: 0rem 8rem;
    align-self: center;
}