html, body, #wrapper {
    height:100%;
    margin:0;
    padding:0;
    overflow: hidden;
}
#wrapper {
    position:relative;
}

#top, #middle, #bottom {
    position:absolute;
}

#top, #bottom {
    width:100%;
    text-align: center;
}

#middle {
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    background: #f5f5f5;
    padding: 12% 100px 50px;
    display: flex;
}

#bottom {
    bottom:0;
}