html, body {
    /* ensure that all of the viewport is used */
    width: 100%;
    height: 100%;
    /* ensure that no scrollbars appear */
    margin: 0;
    padding: 0;

    /* center SVG horizontally and vertically */
    display: flex;
    align-items: center;
    justify-content: center;
}

.scale-fullwidth-svg {
    /* ensure 1:1 aspect ratio, tweak 50 to make SVG larger */
    height: 100vh;
    width: 100vw;
}

.over-img-div {
    width:50vw;
    position: absolute;
    top:40vh;
    bottom: 0;
    left: 0;
    right: 0;
    margin: auto;
}