* {
    box-sizing: border-box;
    flex-wrap: wrap;
}

body {
    font-family: 'Roboto', sans-serif;
    font-size: 16px;
    line-height: 1.5;
    margin: 0;
}

/* Estilos para el encabezado*/
header {
    background-color: black;
    color: lightsteelblue;
    justify-content: space-between;
    padding: 1em;
    font-family: 'IM Fell DW Pica', serif;
    z-index: 1;
    display: flex;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    box-sizing: border-box;
}

nav {
    text-align: right;
}

nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

nav li {
    display: inline-block;
    margin-left: 1em;
}

nav a {
    color: #fff;
    text-decoration: none;
}

nav a:hover {
    text-decoration: underline;
}

a:hover {
    color: black;
    background-color: lightsteelblue;
    border: 5px solid lightsteelblue;
    text-decoration: underline;
}

.icon {
    color: lightsteelblue;
    text-decoration: none;
    padding: 1px;
    font-size: xx-large;
}

.icon:hover {
    color: plum;
    background-color: black;
    text-decoration: none;
    padding: 0px;
    border: none;
}

.biografia {
    color: black;
    background-color: lightsteelblue;
    border: 5px solid lightsteelblue;
    text-decoration: underline;
}

/* Estilos para el main */
main {
    margin-top: 80px;
    padding: 20px;
    background: radial-gradient(white, plum, lightsteelblue, midnightblue);
    display: flex;
    flex-direction: row;
    justify-content: center;
}
h1,h2{
    font-family: 'IM Fell DW Pica', serif;
}
.portadalibro{
    width: 220px;
    height: 300px;
    margin-left: 10px;
}

/* boton */
.button {
    display: inline-block;
    border-radius: 7px;
    border: none;
    background: linear-gradient(black, fuchsia, purple);
    color: white;
    font-family: 'Roboto', sans-serif;
    text-align: center;
    font-size: 13px;
    box-shadow: 0px 14px 56px -11px black;
    width: 10em;
    padding: 1em;
    transition: all 0.4s;
    cursor: pointer;
    left: 50%;
    transform: translateX(-50%);
    margin-left: 120px;
}

.button:hover {
    background: linear-gradient(purple, fuchsia, black);
    box-shadow: none;
    text-decoration: none;
}

.button span {
    cursor: pointer;
    display: inline-block;
    position: relative;
    transition: 0.4s;
}

.button span:after {
    content: 'ya!';
    position: absolute;
    opacity: 0;
    top: 0;
    right: -20px;
    transition: 0.7s;
}

.button:hover span {
    padding-right: 3.55em;
}

.button:hover span:after {
    opacity: 4;
    right: 0;
}

/* containers */
.container_imgydata{
    width: 250px;
}

.container_resumen{
    width: 40%;
    padding: 50px;
    background-color: #fff;
    text-align: center;
}

.saturn{
    width: 80px;
    height: 80px;
}

/*redes*/
.container_redes {
    display: flex;
    flex-direction: row;
    justify-content: end;
    padding: 40px 5px 5px 0px;
    width: 100%;
}

.redes {
    color: beige;
    background-color: violet;
    border: solid gray 1px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    text-decoration: none;
    font-size: x-large;
}

.redes:hover {
    color: #fff;
    background-color: black;
    border: solid 1px black;
    text-decoration: none;
}

/* Estilos para el pie de página */
footer {
    display: flex;
    flex-direction: column;
    background-color: black;
    color: white;
    font-family: 'Times New Roman', Times, serif;
    font-size: small;
    padding: 5px 0px 5px 0px;
}

/*Media querys*/

@media screen and (max-width:900px){
    .container_resumen{
        width: 60%;
    }
} 

@media screen and (max-width:600px){
    .container_resumen{
        width: 100%;
        padding: 10px;
    }
    .container_imgydata{
        width: 300px;
        padding: 20px;
    }
    .container_resumen{
        width: 80%;
    }
} 

@media screen and (max-width:300px){
    header {
        font-size: small;
        height: 100px;
    }
    h2 {
        margin: 0px;
        font-size: 20px;
    }
    .portadalibro{
        width: 120px;
        height: 200px;
        margin-left: 30px;
    }
    .container_imgydata{
        width: 100%;
        padding: 0px;
        margin-bottom: 10px;
    }
    .icon {
        font-size: large;
    }   
    .redes {
        margin: 0px;
    }
    .button {
        font-size: 8px;
        margin-left: 90px;
    }
}