<form class="mailchimp">
<div class="form-group subscribe-form input-round">
<div class="input-group">
<input type="email" name="subscribe" class="form-control" placeholder="Enter Email Address">
<span class="input-group-append">
<button class="button button-dark" type="submit">Sign up
<i class="ti-arrow-right"></i>
</button>
</span>
</div>
<div class="valid-feedback"> </div>
<div class="invalid-feedback"> </div>
</div>
</form>