Twitter引导移动导航

我负责使网站上的移动导航正常工作，但是我遇到了一些问题。

这是到我的代码的链接，问题是它看起来也像我想要的那样，并且该功能有点像我要的那样，当它下拉时，导航栏占据了屏幕的100％，而不是激活滚动条。

我已经尝试使用该代码：overflow: hidden;并且overflow-y: hidden;这些都不起作用。如果链接已过期，则在下面提供一些代码。

     <div class="modal fade" id="myModal" role="dialog">
            <div class="modal-dialog">

                <!-- Modal content-->
                <div class="modal-content">
                    <div class="modal-header">
                        <button class="close" type="button" data-dismiss="modal">×</button>
                        <h4 class="modal-title">Session Timeout</h4>
                    </div>
                    <div class="modal-body">
                        <p>
                            <label>Your session has not been refreshed for 20 minutes, you will be logged out after 30 seconds.  If you wish to continue working click the button below.</label>

                        </p>
                    </div>
                    <div class="modal-footer">


                        <asp:button class="btn btn-default" id="Button1" data-dismiss="modal" onclientclick="stopTimer('<%= FinalTimer.ClientID %>')" text="Continue Working" runat="server">

                    </asp:button></div>
                </div>

            </div>
        </div>


        <div class="navbar navbar-inverse navbar-fixed-top">
            <nav class="navbar navbar-default" role="navigation">
                <div class="navbar-header">
                    <button class="navbar-toggle" type="button" data-target=".navbar-collapse" data-toggle="collapse">
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                    </button>
                </div>


                <div class="navbar-collapse collapse">
<div id="MainMenu">
  <div class="list-group panel">
    <a class="list-group-item list-group-item-success" href="#demo3" data-toggle="collapse" data-parent="#MainMenu">Admin</a>
    <div class="collapse" id="demo3">
      <a class="list-group-item1" href="#SubMenu1" data-toggle="collapse" data-parent="#SubMenu1">Placements<i class="fa fa-caret-down"></i></a>
      <div class="collapse list-group-submenu" id="SubMenu1">
        <a class="list-group-item2" href="#" data-parent="#SubMenu1">New placement</a>
        <a class="list-group-item2" href="#" data-parent="#SubMenu1">End Placement</a>
        <a class="list-group-item2" href="#" data-parent="#SubMenu1">New Referal</a>
        <a class="list-group-item2" href="#" data-parent="#SubMenu1">End Referal</a>
      </div>
      <a class="list-group-item1" href="#SubMenu2" data-toggle="collapse" data-parent="#SubMenu2">Appliences<i class="fa fa-caret-down"></i></a>
      <div class="collapse list-group-submenu" id="SubMenu2">
        <a class="list-group-item2" href="#" data-parent="#SubMenu2">Fridge</a>
        <a class="list-group-item2" href="#" data-parent="#SubMenu2">Freezer</a>
      </div>
      <a class="list-group-item1" href="javascript:;">Backgrounds</a>
    </div>


    <a class="list-group-item list-group-item-success" href="#demo4" data-toggle="collapse" data-parent="#MainMenu">Item 4</a>
    <div class="collapse" id="demo4">
      <a class="list-group-item1" href="">Subitem 1</a>
      <a class="list-group-item1" href="">Subitem 2</a>
      <a class="list-group-item1" href="">Subitem 3</a>
    </div>
  </div>
</div>



                    <ul class="nav navbar-nav navbar-right">
                        <li>
                            <asp:loginview runat="server" viewstatemode="Disabled">
                                <anonymoustemplate>
                                    <ul class="nav navbar-nav navbar-right">
                                        <li><a href="~/Account/Login" runat="server">Log in</a></li>

                                    </ul>
                                </anonymoustemplate>
                                <loggedintemplate>
                                    <ul class="nav navbar-nav navbar-right">
                                        <li>
                                            <asp:loginstatus runat="server" onloggingout="Unnamed_LoggingOut" logoutpageurl="~/" logouttext="Log off" logoutaction="Redirect">
                                        </asp:loginstatus></li>
                                    </ul>
                                </loggedintemplate>
                            </asp:loginview>
                        </li>

                    </ul>
                </div>
            </nav>
        </div>


    .navbar {
  position: relative;
  min-height: 50px;
  border: 1px solid transparent;
    overflow-x:hidden;  
    overflow-y:hidden;
    max-height:100%;
}

.navbar:before,
.navbar:after {
  display: table;
  content: " ";

}

.navbar:after {
  clear: both;

}

.navbar:before,
.navbar:after {
  display: table;
  content: " ";
}

.navbar:after {
  clear: both;
}

任何建议，这将是惊人的。