#paraa {
    margin-top: 10px;
    font-size: 13px;
    text-align: justify;
}

#container123,
.book-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

#container123 {
    margin-bottom: 20px;
}

.book-content {
    min-width: 80%;
    max-width: 400px;
    height: 430px;
    position: relative;
    perspective: 1000px;
    transition: 1s;
    justify-content: center;
}

.book {
    position: absolute;
    width: 65%;
    height: 100%;
    transition: 1s;
    transform-style: preserve-3d;
    transform-origin: left;
}

.face-front,
.face-back {
    width: 100%;
    height: 100%;
    background: white;
    padding: 15px;
    box-sizing: border-box;
    overflow: hidden;
}

.face-front {
    box-shadow: inset 3px 0px 20px -7px black;
    border-top-left-radius: 3px;
    border-bottom-left-radius: 3px;
}

.face-back {
    position: absolute;
    top: 0;
    left: 0;
    transform: translateZ(-1px) rotateY(180deg);
    box-shadow: inset -3px 1px 20px -7px black;
    border-top-right-radius: 3px;
    border-bottom-right-radius: 3px;
}

#portada {
    background-color: #9bdcbe;
}

#portada-back {
    background: url('../img/portadaBack.jpg');
}

#portada,
#portada-back {
    background-size: 100% 100%;
}


/* Clases que se agregaran con Javascript */

.trnsf {
    transform: translateX(200px);
}

.trnsf-reset {
    transform: translateX(0px);
}

/* @media para hacer el texto responsivo */

@media screen and (max-width: 800px) {
    #paraa {
        font-size: 12px;
    }
}