html { overflow: hidden }
body { margin: 0 }
video {
    display: inline-block;
    width: 320px;
    height: 180px;
    position: relative;
    outline: 1px solid black;
}

/* Reset all css properties that can possibly be set on ::cue (8.2.1. The ::cue pseudo-element) to override any system styles. */
::cue {
    color: green;
    opacity: 1;
    visibility: visibile;
    text-decoration: none;
    text-shadow: none;
    background: rgba(0,0,0,0.8);
    outline: none;
    font: 9px Ahem, sans-serif; /* Use Ahem because it improves test reliability. */
    white-space: pre-line;
    text-combine-upright: none;
    ruby-position: alternate;
}