导航条对不齐。。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Hello World</title>
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
</head>
</head>
<body>
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="bavbar-brand" href="#">某管理系统</a>
</div>
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li class="active"><a href="#">首页<span class="sr-only">(current)</span></a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">功能<span class="caret"></span></a>
<ul class="dropdown-menu" role="menu">
<li><a href="#">业务功能</a></li>
<li class="diseabled"><a href="#">信息建立</a></li>
<li><a href="#">信息查询</a></li>
<li class="divider"</li>
<li><a href="#">系统功能</a></li>
<li><a href="#">设置</a></li>
</ul>
</li>
<li><a href="#">帮助</a></li>
</ul>
<form class="navbar-form navbar-left" role="search">
<div class="form-group">
<input type="text" class="form-control" placeholder="用户名">
<input type="password" class="form-control" placeholder="密码">
</div>
<button type="submit" class="btn btn-default">登录</button>
</form>
</div>
</div>
</nav>
<script src=" http://cdn.bootcss.com/jquery/1.11.1/jquery.min.js"></script><!-- Latest compiled and minified JavaScript -->
<script src="http://cdn.bootcss.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
</body>
</html>
