Relative positioning a th in html table
<p>This question came to my mind not because i am doing a project or something. It just popped up in my head.</p>

<p>I have read <em>(from some posts on stack overflow)</em> that <code>position:relative</code> does not affect table elements and that <code>top,left,bottom,right</code> wont work. </p>

<p>I tried this and found that it does affect the <code>th</code> element as shown in below snippet in some way. <code>top</code> and <code>left</code> properties actually worked on <code>th</code>.</p>

<p>But one thing isnt so clear about this effect, why is it that the border of the <code>th</code> stayed at its place and only the <code>th</code> migrated??? Any ideas as to why this happens? </p>

<p>I would really like to know if the border could be moved along with the <code>th</code>.</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-css lang-css prettyprint-override"><code>table {
  border-collapse: collapse;
}
th {
  border: 4px solid green;
  position: relative;
  top: 30px;
  left: 30px;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;table&gt;
  &lt;tr&gt;
    &lt;th&gt;THIS&lt;/th&gt;
  &lt;/tr&gt;
&lt;/table&gt;</code></pre>
</div>
</div>
</p>

<p>Here is a <strong><a href="https://jsfiddle.net/jo_Geek/gna2vgoy/" rel="nofollow noreferrer">fiddle</a></strong></p>