.preview{
    position: fixed;
    top:0;
    bottom: 0;
    left: 0;
    right: 0;
}
.preview-menu{
    position: fixed;
    top:15px;
    bottom: 15px;
    left: 15px;
    width: 300px;
    overflow: auto;
}
.preview-body{
    position: fixed;
    top:15px;
    bottom: 15px;
    right: 15px;
    left: 330px;
}
.preview-page{
    width: 100%;
    height: 100%;
}