有左右和左侧的类来对齐块元素.我想知道导航条是否有相应的上拉和下拉可用？
<header id="navbar" role="banner" class="navbar navbar-fixed-top">
<div class="navbar-inner">
<div class="container">
<!-- .btn-navbar is used as the toggle for collapsed navbar content -->
<a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse">
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</a>
<a class="logo pull-left" href="/" title="Home">
<img src="logo.png" alt="Home">
</a>
<div class="nav-collapse collapse">
<nav role="navigation">
<ul class="menu nav">
<li>...</li>
</ul>
</nav>
</div>
</div>
</div>
</header>
