Firefox fullscreen video append DOM elements : <p>no matter how I put elements in DOM as an overlay on html5 video (statically or dynamically), those elements in Firefox are not visible, although the z-index is set to 2147483647, opacity 1 and display block.</p>

<p>See 2 similar answers, working in Chrome, but not in FF:</p>

<p><a href="https://stackoverflow.com/questions/16234740/overlay-on-html5-fullscreen-video">Overlay on HTML5 Fullscreen Video</a></p>

<p><a href="https://stackoverflow.com/questions/18578244/displaying-elements-other-than-fullscreen-element-html5-fullscreen-api">Displaying elements other than fullscreen element (HTML5 fullscreen API)</a></p>
