(Умный) Липкий Navbar “Sticky”

jQuery(document).ready(function($){ 
var num = 200; //number of pixels before modifying styles 
 
$(window).bind('scroll', function () { 
    if ($(window).scrollTop() > num) { 
        $('.menu').addClass('fixed'); 
    } else { 
        $('.menu').removeClass('fixed'); 
    } 
}); 
});

.fixed { 
    position:fixed; 
    top:0; 
} 
 
.menu { 
    color:#FFF; 
    height:2em; 
    padding:.5em; 
    position:absolute; 
    top:50px; 
    width:100%; 
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> 
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script> 
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous"> 
<div class="menu"> 
<div class="navbar navbar-default" role="navigation"> 
        <div class="container-fluid"> 
          <div class="navbar-header"> 
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse"> 
              <span class="sr-only">Toggle navigation</span> 
              <span class="icon-bar"></span> 
              <span class="icon-bar"></span> 
              <span class="icon-bar"></span> 
            </button> 
            <a class="navbar-brand" href="#">Project name</a> 
          </div> 
          <div class="navbar-collapse collapse"> 
            <ul class="nav navbar-nav"> 
              <li class="active"><a href="#">Link</a></li> 
              <li><a href="#">Link</a></li> 
              <li><a href="#">Link</a></li> 
              <li class="dropdown"> 
                <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a> 
                <ul class="dropdown-menu"> 
                  <li><a href="#">Action</a></li> 
                  <li><a href="#">Another action</a></li> 
                  <li><a href="#">Something else here</a></li> 
                  <li class="divider"></li> 
                  <li class="dropdown-header">Nav header</li> 
                  <li><a href="#">Separated link</a></li> 
                  <li><a href="#">One more separated link</a></li> 
                </ul> 
              </li> 
            </ul> 
            <ul class="nav navbar-nav navbar-right"> 
              <li class="active"><a href="./">Default</a></li> 
              <li><a href="../navbar-static-top/">Static top</a></li> 
              <li><a href="../navbar-fixed-top/">Fixed top</a></li> 
            </ul> 
          </div><!--/.nav-collapse --> 
        </div><!--/.container-fluid --> 
      </div> 
</div> 
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