Twitter bootstrap 如何将mailchimp嵌入表单集中在twitter引导页面中？

这是嵌入代码

     <!-- Begin MailChimp Signup Form -->
<link href="//cdn-images.mailchimp.com/embedcode/slim-081711.css" rel="stylesheet" type="text/css">
<style type="text/css">
    #mc_embed_signup{background:#fff; clear:left; font:14px Helvetica,Arial,sans-serif; }
    /* Add your own MailChimp form style overrides in your site stylesheet or in this style block.
       We recommend moving this block and the preceding CSS link to the HEAD of your HTML file. */
</style>
<div id="mc_embed_signup">
<form action="http://unityi.us2.list-manage.com/subscribe/post?u=a93bfac69d884f15e416661bb&amp;id=4618e101c1" method="post" id="mc-embedded-subscribe-form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>

    <input type="email" value="" name="EMAIL" class="email" id="mce-EMAIL" placeholder="email address" required>
    <div class="clear"><input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button"></div>
</form>
</div>

<!--End mc_embed_signup-->

#mc_embed_注册{背景：fff；清除：左；字体：14px Helvetica，Arial，无衬线；}
/*在站点样式表或此样式块中添加您自己的MailChimp表单样式替代。
我们建议将此块和前面的CSS链接移动到HTML文件的头部*/

添加属性“display:block”和“margin:auto”就可以了。您也可以将表单放在网格中，尽管这样会更复杂

您可以只添加中心标记吗？我已经试过了，效果很好。简单回答：）

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</style>

<!-- ADD HERE -->
**<center>**

<div id="mc_embed_signup">
<form action="http://unityi.us2.list-manage.com/subscribe/post?   u=a93bfac69d884f15e416661bb&amp;id=4618e101c1" method="post" id="mc-embedded-subscribe- form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>

<input type="email" value="" name="EMAIL" class="email" id="mce-EMAIL" placeholder="email address" required>
<div class="clear"><input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button"></div>
</form>
</div>

<!-- AND CLOSE HERE -->
**</center>**

<!--End mc_embed_signup-->