text: // Navbar vertical align
  //
  // Vertically center elements in the navbar.
  // Example: an element has a height of 30px, so write out `.navbar-vertical-align(30px);` to calculate the appropriate top margin.
  
  @mixin navbar-vertical-align($element-height) {
    margin-top: (($navbar-height - $element-height) / 2);
    margin-bottom: (($navbar-height - $element-height) / 2);
  }
  