body, html {
    overflow: hidden;
    width: 100%;
    height: 100%;
    background: #FFF url('../images/bg.jpg') no-repeat center center;
}

#flipbook {
    border: 1px solid #333;
    box-shadow: 0px 0px 50px rgba(0,0,0,0.8);
    width: 1400px;
    height: 1000px;
    margin: 0px auto;
    margin-top: 50px;
    background-color: rgba(0,0,0,0.6);
}

#a {
    cursor: pointer;
    background: #FFF url('../images/meghivo1.jpg') no-repeat center center;
    background-size: contain;
}
#b {
    cursor: pointer;
    background: #FFF url('../images/meghivo2.jpg') no-repeat center center;
    background-size: contain;
}
#c {
    cursor: pointer;
    background: #FFF url('../images/meghivo3.jpg') no-repeat center center;
    background-size: contain;
}
#d {
    cursor: pointer;
    background: #FFF url('../images/meghivo4.jpg') no-repeat center center;
    background-size: contain;
}