body{
    display: flex;
    flex-direction: column;
}

.principal{
    margin-left: 5%;
    margin-right: 5%;
}

h1{
    margin-left: auto;
    margin-right: auto;
    color: gray;
}

h5{
    margin-left: 35%;
}

.principal{
    display: flex;
}

.cuadro{
    background-color: darkgray;
    width: 10rem;
    height: 10rem;
}

ul{
    color: tomato;
}

.principal a{
    text-decoration: none;
    color: black;
}

.oferta{
    margin-left: auto;
    margin-right: auto;
    justify-content: center;
    text-align: center;
    width: 60%;
}

.oferta h2{
    text-align: center;
    background-color: #16407D;
    color: white;
    padding: 1%;
}

img{
    width: 90%;
}

.subtitulo{
    margin-left: auto;
    margin-right: auto;
    color: #1c51a1;
}

.pdf{
    width: 90%;
    height: 50rem;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 5rem;
}

@media only screen and (min-width: 310px) and (max-width: 616px) {
    .cuadro{
        height: 17rem;
    }

    .oferta{
        width: 80%;
    }    

    .pdf{
        width: 90%;
        height: 20rem;
    }
 }