title: mPDF : text align with p , h1 - h6 in table not work
body: <p>this code not work in table with mPDF php class 
  <a href="https://i.stack.imgur.com/lqQB7.png" rel="noreferrer"><img src="https://i.stack.imgur.com/lqQB7.png" alt="enter image description here"></a></p>
  
  <pre><code>    &lt;table&gt;
      &lt;tr&gt;
        &lt;td class="contentDetails"&gt;
    &lt;td class="contentDetails"&gt;
           &lt;h3 style="text-align: right;"&gt;&lt;strong&gt;text align right&lt;/strong&gt;&lt;/h3&gt;
           &lt;h3 style="text-align: center;"&gt;&lt;strong&gt;text align center&lt;/strong&gt;&lt;/h3&gt;
           &lt;h3 style="text-align: left;"&gt;&lt;strong&gt;text align left&lt;/strong&gt;&lt;/h3&gt;
       &lt;/td&gt;
      &lt;/tr&gt;
      &lt;/table&gt;
  </code></pre>
  
  <p>i triad use </p>
  
  <pre><code>.contentDetails &gt; h3 {display: block;} 
  </code></pre>
  
  <p>but not work and between td it's html from Editor tinymce</p>
  
  <p>this full code from script 
  and when do output found content the td text align left not right or center</p>
  
  <pre><code>&lt;?php
  
  $html = '
  &lt;h1&gt;mPDF&lt;/h1&gt;
      &lt;table style="border-collapse: collapse;
      font-size: 12px;
      font-weight: 700;
      margin-top: 5px; 
      border-top: 1px solid #777;
      width: 100%;"&gt;
  &lt;tbody&gt;
  &lt;tr&gt;
    &lt;td class="contentDetails"&gt;
           &lt;h3 style="text-align: right;"&gt;&lt;strong&gt;text align right&lt;/strong&gt;&lt;/h3&gt;
           &lt;h3 style="text-align: center;"&gt;&lt;strong&gt;text align center&lt;/strong&gt;&lt;/h3&gt;
           &lt;h3 style="text-align: left;"&gt;&lt;strong&gt;text align left&lt;/strong&gt;&lt;/h3&gt;
       &lt;/td&gt;
  &lt;/tr&gt;
  &lt;/tbody&gt;
  &lt;/table&gt;';
  
  include("mpdf.php");
  
  $mpdf=new mPDF('c'); 
  $mpdf-&gt;WriteHTML($html);
  
  $mpdf-&gt;Output();
  
  exit;
  ?&gt;
  </code></pre>