title: Expand/collapse mobile navbar without JavaScript
body: <p>On mobile devices, Bootstrap 3 by default reduces the navigation bar (navbar) to a hamburger icon. When clicking the hamburger, a JavaScript toggles the display of the navigation menu items - either expanding or collapsing the navbar. But</p>
  
  <h1>how to toggle the bootstrap mobile navbar collapse/expand without requiring JavaScript?</h1>
  
  <p>If this were possible, it would have nice <strong>performance advantages</strong>: users can already navigate before JavaScript is executed (a good plus on flaky mobile connections), and smaller projects may be able to drop the dependency on jQuery + bootstrap javascript entirely, saving around 45k on first page load. Plus, the site becomes more <strong> robust in case of JS errors</strong> - at least the page navigation stays usable.</p>
  
  <p>Alternatively, one could <a href="http://thednp.github.io/bootstrap.native/" rel="noreferrer">re-implement the bootstrap JS without jQuery dependency</a> - done <a href="http://mpetroff.net/2015/03/bootstrap-navbar-without-jquery/" rel="noreferrer">here</a> for the navbar.</p>
  
  <p>For reference, this is what the <a href="http://getbootstrap.com/examples/navbar-static-top/" rel="noreferrer">static navbar top</a> example looks like in mobile mode:</p>
  
  <p><img src="https://i.stack.imgur.com/nrHRs.png" alt="Bootstrap 3 mobile navbar expanded"></p>