When a site has a "system message" shown (such as the message shown on recently launched beta sites, like [Vi/Vim](//vi.stackexchange.com)), the mobile layout suffers: 

![message][1]

Compare the above with how the mobile navigation bar normally looks:

![normal][2]

Worse yet, a selected tab on the navigation bar is shown in white on white: 

![selected][3]

Observed in mobile Opera 27 on Android, and also in desktop Chrome 41 on Chrome OS, from where the screenshots are taken. 

The problem is that  `<div class="system-message-container">` is positioned where the navigation bar is supposed to be; if it is  deleted, the normality is restored.



  [1]: https://i.sstatic.net/WPxbd.png
  [2]: https://i.sstatic.net/xySVx.png
  [3]: https://i.sstatic.net/5J10o.png