AngularJS Twitter Bootstrap dropdown menu inside Nav bar

I am trying include a dropdown menu inside a navbar with Angular-UI Bootstrap. Please see this plnkr I played with css and i can get it to working on desktop version. But when it comes to mobile view, there are many other styles that I got to do. So clearly I am doing something wrong. Can some one show me what i am doing wrong.

<nav class="navbar navbar-inverse">

    <div class="navbar-header">
        <a href="/" class="navbar-brand"><span class="brand-title"></span></a>
        <a class="btn navbar-btn navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </a>
    </div>
    <div class="navbar-collapse collapse" >
        <div class="pull-left navbar-logo">
            <ul class="nav navbar-nav" >
                <li>
                    <a data-ng-href="#/Search">Search</a>
                </li>
                 <li>
                    <a data-ng-href="#/Search">Search2</a>
                </li>
              <div class="btn-group" uib-dropdown >
                <a id="single-button"   uib-dropdown-toggle ng-disabled="disabled">
                  Button dropdown <span class="caret"></span>
                </a>
                <ul uib-dropdown-menu role="menu" aria-labelledby="single-button">
                  <li role="menuitem"><a href="#">Action</a></li>
                  <li role="menuitem"><a href="#">Another action</a></li>
                  <li role="menuitem"><a href="#">Something else here</a></li>
                  <li class="divider"></li>
                  <li role="menuitem"><a href="#">Separated link</a></li>
                </ul>
              </div>
            </ul>
        </div>

    </div>
</nav>