使bootstrap导航栏菜单垂直

Question

我有一个水平的bootstrap导航栏菜单。这是样式代码

<style>
.dropdown-large {
  position: static !important;
}
.dropdown-menu-large {
  margin-left: 16px;
  margin-right: 16px;
  padding: 20px 0px;
}
.dropdown-menu-large > li > ul {
  padding: 0;
  margin: 0;
}
.dropdown-menu-large > li > ul > li {
  list-style: none;
}
.dropdown-menu-large > li > ul > li > a {
  display: block;
  padding: 3px 20px;
  clear: both;
  font-weight: normal;
  line-height: 1.428571429;
  color: #333333;
  white-space: normal;
}
.dropdown-menu-large > li ul > li > a:hover,
.dropdown-menu-large > li ul > li > a:focus {
  text-decoration: none;
  color: #262626;
  background-color: #f5f5f5;
}
.dropdown-menu-large .disabled > a,
.dropdown-menu-large .disabled > a:hover,
.dropdown-menu-large .disabled > a:focus {
  color: #999999;
}
.dropdown-menu-large .disabled > a:hover,
.dropdown-menu-large .disabled > a:focus {
  text-decoration: none;
  background-color: transparent;
  background-image: none;
  filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
  cursor: not-allowed;
}
.dropdown-menu-large .dropdown-header {
  color: #428bca;
  font-size: 18px;
}
@media (max-width: 768px) {
  .dropdown-menu-large {
    margin-left: 0 ;
    margin-right: 0 ;
  }
  .dropdown-menu-large > li {
    margin-bottom: 30px;
  }
  .dropdown-menu-large > li:last-child {
    margin-bottom: 0;
  }
  .dropdown-menu-large .dropdown-header {
    padding: 3px 15px !important;
  }
}


</style>

这是HTML部分

<div class="collapse navbar-collapse js-navbar-collapse">
        <ul class="nav navbar-nav">
            <li class="dropdown dropdown-large">
                <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>

                <ul class="dropdown-menu dropdown-menu-large row">
                    <li class="col-sm-3">
                        <ul>
                            <li class="dropdown-header">Glyphicons</li>
                            <li><a href="#">Available glyphs</a></li>
                            <li class="disabled"><a href="#">How to use</a></li>
                            <li><a href="#">Examples</a></li>
                            <li class="divider"></li>
                            <li class="dropdown-header">Dropdowns</li>
                            <li><a href="#">Example</a></li>
                            <li><a href="#">Aligninment options</a></li>
                            <li><a href="#">Headers</a></li>
                            <li><a href="#">Disabled menu items</a></li>
                        </ul>
                    </li>
                    <li class="col-sm-3">
                        <ul>
                            <li class="dropdown-header">Button groups</li>
                            <li><a href="#">Basic example</a></li>
                            <li><a href="#">Button toolbar</a></li>
                            <li><a href="#">Sizing</a></li>
                            <li><a href="#">Nesting</a></li>
                            <li><a href="#">Vertical variation</a></li>
                            <li class="divider"></li>
                            <li class="dropdown-header">Button dropdowns</li>
                            <li><a href="#">Single button dropdowns</a></li>
                        </ul>
                    </li>
                    <li class="col-sm-3">
                        <ul>
                            <li class="dropdown-header">Input groups</li>
                            <li><a href="#">Basic example</a></li>
                            <li><a href="#">Sizing</a></li>
                            <li><a href="#">Checkboxes and radio addons</a></li>
                            <li class="divider"></li>
                            <li class="dropdown-header">Navs</li>
                            <li><a href="#">Tabs</a></li>
                            <li><a href="#">Pills</a></li>
                            <li><a href="#">Justified</a></li>
                        </ul>
                    </li>
                    <li class="col-sm-3">
                        <ul>
                            <li class="dropdown-header">Navbar</li>
                            <li><a href="#">Default navbar</a></li>
                            <li><a href="#">Buttons</a></li>
                            <li><a href="#">Text</a></li>
                            <li><a href="#">Non-nav links</a></li>
                            <li><a href="#">Component alignment</a></li>
                            <li><a href="#">Fixed to top</a></li>
                            <li><a href="#">Fixed to bottom</a></li>
                            <li><a href="#">Static top</a></li>
                            <li><a href="#">Inverted navbar</a></li>
                        </ul>
                    </li>
                </ul>

            </li>
        </ul>

    </div>

。菜单目前处于横向状态，我试图将其垂直放置，但我无法提供解决方案。

有人可以帮我把菜单垂直吗？

提前致谢