body, html {
    margin: 0;
    padding: 0;
    height: 100%;
    width: 100%;
    overflow: hidden; /* Disables scrolling on the main window */
}

#background-frame {
    width: 100%;
    height: 100%;
    display: block;
    border: none;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1; /* Sits behind any potential future overlays */
}