I have found that by adding some JavaScript in the <head>
, the page waits for the style to load before the focus.
I'm not exactly sure why this works, but it does!
Example:
<script type="text/javascript">
// Fix for Firefox autofocus CSS bug
// See: http://stackoverflow.com/questions/18943276/html-5-autofocus-messes-up-css-loading/18945951#18945951
</script>