html, body {
    margin: 0;
    height: 100%;
}
 
body {
    background-color: #333;
}
 
body.hide-overflow {
    overflow-x: hidden;
}
 
/* helpers */
 
.flipbook-viewport {
    display: table;
    width: 100%;
    height: 100%;
}
 
.container {
    display: table-cell;
    vertical-align: middle;
    text-align: center;
}
 
.fbrel {
    position: relative;
}
 
/* book */
 
.flipbook {
    margin: 0 auto;
    width: 90%;
    height: 90%;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}
 
.flipbook .page {
    height: 100%;
}
 
.flipbook .page img {
    max-width: 100%;
    height: 100%;
}