How do I get navigation menu on top with narrow viewport? I'm running Drupal 7.28 with Zen 7.x-5.5.  In the default setup, there is a region on the right side named "First sidebar" which contains a block named "Navigation".  I have put my navigation links there.  When shrinking the width of the browser to see how my site will be rendered on a mobile the navigation block gets positioned at the bottom of the page.

I want the navigation to be at the top in a mobile scenario, ideally with a bootstrap-esque collapsed menu.  How can I achieve this?
@media width queries in CSS
http://css-tricks.com/css-media-queries/
At a certain width, you could use a different positioning tactic, forcing it up top.
Via Javascript, checking against: window.innerWidth or body .clientWidth
Many things you could do here, from changing CSS rules, to actually moving it in the DOM.
Using a Drupal module for responsive menus like:
https://www.drupal.org/project/responsive_navigation
or https://www.drupal.org/project/responsive_menus