This situation is strange. When I open my website (built on bootstrap) on small screens navbar is visible, but it should be collapse. When I click on button to collapse, it is still visible, when I click second time it is collapse just now. And since that it works good. But when I reload page, I still have this issue.
<div class=container>
<!--MENU-->
<nav style="border-bottom:1px solid #000;">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed menu_button" data-toggle="collapse" data-target=".nbar" aria-expanded="false">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
</div>
<div class="container nbar">
<ul class="nav nav-justified">
<li><a href=#>o nas</a></li>
<li><a href=#>galeria</a></li>
<li><a href=#>blog</a></li>
<li><a href=#>kontakt</a></li>
</ul>
</div>
</nav>