twitter-bootstrap - mailchimp 埋め込みフォームを Twitter ブートストラップ ページの中央に配置するにはどうすればよいですか?

Question

ここに埋め込みコードがあります。

     <!-- 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-->