Can you try adding:
<meta name="viewport" content="initial-scale=1.0, maximum-scale=2.0, width=device-width, user-scalable=yes, minimal-ui">
<meta name="HandheldFriendly" content="true">
<meta name="MobileOptimized" content="320">
Moreover, I found your issue for not showing up the content on mobile (line 79.):
When I remove it or put to
visible, I see the text, and sharing boxes on the bottom of the screen, etc.
See on the screenshot below: