*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:Arial, Helvetica, sans-serif;
}

body{
    background:#ffffff;
    color:#333;
}

header{
    background:#fff;
    padding:30px 0;
    text-align:center;
}

header img{
    width:180px;
}

.introduccion{
    width:60%;
    margin:20px auto 40px;
    text-align:center;
}

.introduccion h1{
    font-size:30px;
    color:#57A519;
    margin-bottom:15px;
}

.introduccion p{
    font-size:16px;
    color:#666;
    line-height:1.6;
}

/* CATÁLOGO */

.catalogo{
    width:1200px;
    margin:0 auto;
    display:grid;
    grid-template-columns:repeat(5, 1fr);
    gap:40px;
   margin-bottom: 200px;
}

/* TARJETA */

.libro{

    text-align:center;

}

.libro img{

    width:100%;
    height:250px;
    object-fit:contain;

}

.libro h3{

    margin-top:12px;
    font-size:16px;
    font-weight:bold;
    color:#333;
    line-height:1.3;

}

.libro p{

    margin-top:12px;
    color:#666;
    font-size:15px;

}

.libro span{

    display:block;
    margin-top:4px;
    color:#777;
    font-size:14px;

}