为什么一样的代码效果不一样
<div class="navbar navbar-default"> <div class="navbar-header"> <a href="#" class="navbar-brand">慕课网</a> </div> <ul class="nav navbar-nav"> <li class="active"><a href="#">网站首页</a></li> <li> <a href="#" data-toggle="dropdown" class="dropdown-toggle"> 系列教程 <span class="caret"></span> </a> <ul class="dropdown-menu"> <li><a href="#">CSS3</a></li> <li><a href="#">Javascript</a></li> <li><a href="#">PHP</a></li> </ul> </li> <li><a href="#">名师介绍</a></li> <li><a href="#">成功案例</a></li> <li><a href="#">关于我们</a></li> </ul> <form action="#" class="navbar-form navbar-left" role="search"> <div class="form-group"> <input type="text" class="form-control" placeholder="请输入关键词" /> </div> <button type="submit" class="btn btn-default">搜索</button> </form> </div> <div class="navbar navbar-default" role="navigation"> <div class="navbar-header"> <a href="##" class="navbar-brand">慕课网</a> </div> <ul class="nav navbar-nav"> <li class="active"><a href="##">网站首页</a></li> <li class="dropdown"> <a href="##" data-toggle="dropdown" class="dropdown-toggle">系列教程<span class="caret"></span></a> <ul class="dropdown-menu"> <li><a href="##">CSS3</a></li> <li><a href="##">JavaScript</a></li> <li class="disabled"><a href="##">PHP</a></li> </ul> </li> <li><a href="##">名师介绍</a></li> <li><a href="##">成功案例</a></li> <li><a href="##">关于我们</a></li> </ul> <form action="##" class="navbar-form navbar-left" rol="search"> <div class="form-group"> <input type="text" class="form-control" placeholder="请输入关键词" /> </div> <button type="submit" class="btn btn-default">搜索</button> </form> </div>
代码一样的，效果却不一样，后面是网站上
的代码
