title: How to add space between elements so they fill their container div?
body: <p>I want to add space between <em>spans</em> so that the leftmost and rightmost spans will be close to the edges of the <em>inner div</em>. I've tried to add the following rule, but it had no effect.</p>
  
  <pre class="lang-css prettyprint-override"><code>span.icon-square {
      margin: 0 auto;
  }
  
  span.icon-square:first-child {
      margin-left: 0;
  }
  
  span.icon-square:last-child {
      margin-right: 0;
  }
  </code></pre>
  
  <p>The illustration of what I'm trying to achieve is given below:</p>
  
  <p><a href="https://i.stack.imgur.com/ETtyQ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ETtyQ.png" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/mI22i.png" rel="noreferrer"><img src="https://i.stack.imgur.com/mI22i.png" alt="enter image description here"></a></p>
  
  <p>So, what am I missing?</p>