Possible to Add ‘outline: none’ to #noVNC_canvas?

For aesthetics, we currently add max-height: none to .full-gui-frame-outer, per 2.png, in order to hide the gray background, as would otherwise appear, per 1.png. However, per 4.png, because the X11 iframe has height: 720px, clicking anywhere within those 720px results in a glowing bottom border (in Chrome on macOS, at least), per 3.png, because the element is getting focus. Adding outline: none to #noVNC_canvas would seem to avoid that blue line. (It’s okay if the region below that blue line still isn’t usable, but trying to avoid the gray background when the viewport is > 720px.