问题如图，上面展示效果为放入栅格系统，下面未放入。在小视口时页面样式有些元素超出父盒子，在大视口时页面样式无问题。请问如何解决

<div class="container">
    <div class="row">
        <div class="col-md-12">
            <div class="navbar navbar-default">
                <div class="navbar-header">
                    <a href="##" class="navbar-brand">
                       某管理系统 
                    </a>
                </div>
                <ul class="nav navbar-nav">
                    <li><a href="##">首页</a></li>
                    <li class="dropdown">
                        <a class="dropdown-toggle" data-toggle="dropdown" href="##">功能<span class="caret"></span></a>
                        <ul class="dropdown-menu">
                            <li class="dropdown-header">业务功能</li>
                            <li><a href="##">信息</a></li>
                            <li class="acitve"><a href="##">管理</a></li>
                            <li class="divider"><a href="##"></a></li>
                            <li class="dropdown-header">管理功能</li>
                            <li><a href="##">设置</a></li>
                        </ul>
                    </li>
                    <li><a href="##">帮助</a></li>
                </ul>
                <form class="navbar-form navbar-right">
                    <input type="text" class="form-control" placeholder="用户名">
                    <input type="text" class="form-control" placeholder="密码">
                    <a class="btn btn-primary" href="##">登录</a>
                </form>
            </div>
        </div>
    </div>
</div>