<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="container">
<div class="row">
<div class="row">
<div class="row">
<div class="block">
<a href="https://www.xbootstrap.com/"><i class="hoverbtn effect-5 sub-a">Hover Over</i></a>
</div>
<div class="block">
<i class="hoverbtn effect-6">Hover Over</i>
</div>
<div class="block">
<i class="hoverbtn effect-7 sub-a">Hover Over</i>
</div>
<div class="block">
<i class="hoverbtn effect-7 sub-b">Hover Over</i>
</div>
</div>
<div class="row">
<div class="block">
<i class="hoverbtn effect-8">Hover Over</i>
</div>
<div class="block">
<i class="hoverbtn effect-9 sub-a">Hover Over</i>