HTML Example:

<!-- START: MailChimp Signup Form -->
<form action="//nkdev.us11.list-manage.com/subscribe/post?u=d433160c0c43dcf8ecd52402f&id=7eafafe8f0" method="post" class="nk-mchimp validate" target="_blank">
    <div class="input-group">
        <input type="email" value="" name="EMAIL" class="required email form-control text-xs-center" placeholder="Email *">
        <button class="nk-btn nk-btn-block nk-btn-color-dark-1">Subscribe</button>
    </div>
    <div class="nk-form-response-success"></div>
    <div class="nk-form-response-error"></div>
    <!-- real people should not fill this in and expect good things - do not remove this or risk form bot signups-->
    <div style="position: absolute; left: -5000px;" aria-hidden="true"><input type="text" name="b_d433160c0c43dcf8ecd52402f_7eafafe8f0" tabindex="-1" value=""></div>
</form>
<!-- END: MailChimp Signup Form -->