div#resizer_overlay {
    position: fixed;
    top: 0; left: 0;
    right:0; bottom:0;
    background-color: rgba(0,0,0,.7);
    display: none;
    z-index: 100;
    height: 100%;
}

img#resized_image {
    max-width: 98vw;
    max-height: 98vh;
    margin: 1vh auto;
    display: block;
}