body {
    text-align: center;
    font-family: Arial;
    background: #f5f5f5;
}

#book {
    width: 400px;
    height: 600px;
    margin: auto;
}

.page img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

button {
    padding: 10px;
    margin: 10px;
    cursor: pointer;
}