<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
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<div class="container">
<h1 class="text-center m-5">SUBSCRIBE TO OUR NEWSLETTER</h1>
</div>
<section class="bg-dark text-center p-5 mt-4">
<div class="container p-3">
<h3 class="text-white">SUBSCRIBE NOW</h3>
<form action="#" method="Post">
<input type="text" name="text" placeholder="Enter Your Email Id">
<button type="button" class="btn btn-default">Subscribe<i class="fa fa-envelope"></i></button>
</form>
</div>
</section>
<section class="bg-warning text-center p-5 mt-4">
<div class="container p-3">
<h3>SUBSCRIBE NOW</h3>
<form action="#" method="Post">
<input type="text" name="text" placeholder="Enter Your Email Id">
<button type="button" class="btn btn-secondary">Subscribe</button>
</form>
</div>
</section>
<section class="bg-secondary text-center p-5 mt-4">
<div class="container p-3">
<h3>SUBSCRIBE NOW</h3>
<form action="#" method="Post">
<input type="text" name="text" placeholder="Enter Your Email Id">
<button type="button" class="btn btn-success">Subscribe</button>
</form>
</div>
</section>
