Elements pushed down after enlargement
<p>I have created something that enlarges divs when they are hovered on, using <code>onmouseover</code>. They shrink back to their normal size, using <code>onmouseout</code>. But, for some reason, the divs are pushed down and stay there. This causes one of the divs to start glitching. How can I stop the divs from being pushed down, but still have the divs being enlarged and becoming smaller?
<strong>UPDATE</strong>
It has happened again when I put it with the rest of my code.
<a href="https://jsfiddle.net/pc65ve7b/" rel="nofollow">https://jsfiddle.net/pc65ve7b/</a></p>

<p>Can someone help me please?</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function enlarge(a, b, c, d) {
   a.style.height = "375px";
   b.style.height = "0px";
   c.style.height = "0px";
   d.style.height = "0px";
 };

 function shrink(a, b, c, d) {
   a.style.height = "125px";
   b.style.height = "125px";
   c.style.height = "125px";
   d.style.height = "125px";
 };</code></pre>
<pre class="snippet-code-css lang-css prettyprint-override"><code>.thing {
  height: 125px;
  width: 250px;
  z-index: 10;
  position: relative;
  border: 5px solid brown;
}
.aside {
  border: 5px solid black;
  overflow:hidden;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;aside class="aside"&gt;
  &lt;div id="c1"&gt;&lt;/div&gt;
  &lt;div class="thing" style="background-color: blue;" id="c2" onmouseover="enlarge(this, document.getElementById('c1'), document.getElementById('c3'), document.getElementById('c4'))" onmouseout="shrink(this, document.getElementById('c1'), document.getElementById('c3'), document.getElementById('c4'))"&gt;&lt;h1&gt;hello&lt;/h1&gt;&lt;/div&gt;
  &lt;div class="thing" style="background-color: orange;" id="c3" onmouseover="enlarge(this, document.getElementById('c1'), document.getElementById('c2'), document.getElementById('c4'))" onmouseout="shrink(this, document.getElementById('c1'), document.getElementById('c2'), document.getElementById('c4'))"&gt;&lt;h1&gt;hello&lt;/h1&gt;&lt;/div&gt;
  &lt;div class="thing" style="background-color: pink" id="c4" onmouseover="enlarge(this, document.getElementById('c1'), document.getElementById('c2'), document.getElementById('c3'))" onmouseout="shrink(this, document.getElementById('c1'), document.getElementById('c2'), document.getElementById('c3'))"&gt;&lt;h1&gt;hello&lt;/h1&gt;&lt;/div&gt;
&lt;/aside&gt;</code></pre>
</div>
</div>
</p>