how vertically center link in div
<p>The search now link is stuck aligned to the top of the div.  How do I make this link centered vertically in the div?</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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<pre class="snippet-code-css lang-css prettyprint-override"><code>.advanced-button {
  width: 200px;
  height: 55px;
  background-color: #f4c23d;
  line-height: 40px;
}
.advanced-button a {
  margin-left: 15px;
  font-size: 16px;
  font-family: 'Montserrat', sans-serif;
  color: #222222;
  font-weight: 700;
  text-transform: uppercase;
  vertical-align: middle;
}
.advanced-button i {
  float: right;
  width: 40px;
  height: 55px;
  line-height: 40px;
  text-align: center;
  background-color: #f0b20e;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="advanced-button"&gt;
  &lt;a href="#"&gt;Search Now&lt;i class="fa fa-search"&gt;&lt;/i&gt;&lt;/a&gt;
&lt;/div&gt;</code></pre>
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