I don't know how, but it happens: jsfiddle
When showing twitter bootstrap 3 modal, it goes behind video iframe.
<div class="modal fade">
...
</div><!-- /.modal -->
<iframe src="http://www.youtube.com/embed/your_favorite_video" allowfullscreen="" ></iframe>
it seems z-index cannot help too.
UPDATE:
I use Mozilla Firefox 25.0.1 for ubuntu canonical 1.0.
Other browers are fine:
- Mozilla Firefox on windowse is fine
- Opera on Ubuntu is fine
- ...