Font Awesome 5.0.0 SVG

HTML

<script src="https://use.fontawesome.com/releases/v5.0.0/js/all.js"></script>
<div style="text-align: center; display: inline-block;" >

<div class="fa-2x" >
  <i class="fas fa-square" ></i> 
  +
  <i class="fas fa-code" ></i><br />
  =
</div>

<br />
<div class="fa-stack" >
  <i class="fas fa-square fa-stack-2x" ></i> <br />
  <i class="fas fa-code fa-stack-1x fa-inverse" ></i>
</div>

</div>

CSS

body {
  font-size: 16px;
}