mPDF : text align with p , h1 - h6 in table not work - php

Question

this code not work in table with mPDF php class
<table>
<tr>
<td class="contentDetails">
<td class="contentDetails">
<h3 style="text-align: right;"><strong>text align right</strong></h3>
<h3 style="text-align: center;"><strong>text align center</strong></h3>
<h3 style="text-align: left;"><strong>text align left</strong></h3>
</td>
</tr>
</table>
i triad use
.contentDetails > h3 {display: block;}
but not work and between td it's html from Editor tinymce
this full code from script
and when do output found content the td text align left not right or center
<?php
$html = '
<h1>mPDF</h1>
<table style="border-collapse: collapse;
font-size: 12px;
font-weight: 700;
margin-top: 5px;
border-top: 1px solid #777;
width: 100%;">
<tbody>
<tr>
<td class="contentDetails">
<h3 style="text-align: right;"><strong>text align right</strong></h3>
<h3 style="text-align: center;"><strong>text align center</strong></h3>
<h3 style="text-align: left;"><strong>text align left</strong></h3>
</td>
</tr>
</tbody>
</table>';
include("mpdf.php");
$mpdf=new mPDF('c');
$mpdf->WriteHTML($html);
$mpdf->Output();
exit;
?>

Answer 1

Try the below code. I think it will help you.
<table width="100%">
<tr>
<td class="contentDetails">
<th align="left"> <h3><strong>text align right</strong></h3></th>
<th align="center"> <h3><strong>text align center</strong></h3></th>
<th align="right"> <h3><strong>text align left</strong></h3></th>
</td>
</tr>
</table>
using extra tags in this.

Answer 2

I have prepared a lot of hours a content to print (mPdf v.6). Now i can give an advice to all. Don't use tables to align content or simply hold the content. Almost all css properties of elements work fine. But - but must not be nested in table.

Answer 3

The problem is the width of the container which is fitting with the content. Set table width to 100%
table {
width: 100%;
}
<table>
<tr>
<td class="contentDetails">
<h3 style="text-align: right;"><strong>text align right</strong></h3>
<h3 style="text-align: center;"><strong>text align center</strong></h3>
<h3 style="text-align: left;"><strong>text align left</strong></h3>
</td>
</tr>
</table>