#maskHiddenOrNot{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9999;
    background: #fff;
    box-sizing: border-box;
    padding: 20px;
}
#mainWindowHiddenOrNot{
    width: 100%;
    height: 100%;
    box-sizing: border-box;
}