Bootstrap调整响应式偏移问题

Question

] 调整浏览器大小时，偏移量无效...

当我调整浏览器的大小时，这些元素并没有集中在他们的控制方式......表单堆叠了horzinotal并且项目向左浮动而不是居中他们必须在未调整大小的浏览器中的方式

<div class="container">
    <div class="row">
        <div class="col-md-6 col-md-offset-3" style="margin-top:8%">
            <h2 class="text-center">Log In To Your Account</h2>
        </div>
    </div>
    <div class="row">
        <div  class="col-md-6 col-md-offset-3">
            <div role="form" id="loginForm">
                <div class="form-group">
                    <label for="logLogin"><h4>Login</h4></label>
                    <input type="text" placeholder="Login Here..." id="logLogin" class="form-control">
                </div>
                <div class="form-group">
                    <label for="logPass"><h4>Password</h4></label>
                    <input type="password" placeholder="Password Here..." id="logPass" class="form-control">
                </div>
                <div class="row">
                <div class="col-md-5 col-md-offset-4">
                <div class="form-group">
                        <input type="submit" value="Log In" class="btn btn-danger btn-lg" id="loginSubmit"> 
                </div>
                </div>
                </div>
            </div>
        </div>      
    </div>
    <div class="row">
        <div class="col-md-12">
            <mdall>
                <h4 class="text-center"><strong>...0r Join Us With</strong></h4>
            </mdall>
        </div>  
    </div>
    <div class="row">
        <div class="col-md-8 col-md-offset-4">      
            <ul class="list-inline">
                <li><a href="facebook.com"><span class="fa fa-facebook-official " aria-hidden="true"></span> Facebook</a></li>
                <li><a href="twitter.com"><span class="fa fa-twitter" aria-hidden="true"></span> Twitter</a></li>
                <li><a href="youtube.com"><span class="fa fa-youtube " aria-hidden="true"></span> Youtube</a></li>
                <li><a href="instagram.com"><span class="fa fa-instagram " aria-hidden="true"></span> Instagram</a></li>
            </ul>
        </div>  
    </div>
</div>