html – Why cannot a category attribute from a container tag have an effect on a nested desk factor inside it the container tag

I’ve a category attribute inside a <div> tag that modifications the coloration: property. I am questioning why on this case why that class attribute does not change the nested desk factor’s properties, because the nested h1 factor within the container tag has its coloration modified.

I’ve tried placing the category attribute within the desk factor and that solved the issue, however I am questioning why the category attribute within the div tag does not have an effect on the desk factor’s properties for the code beneath. Thanks if somebody solutions.

.check {
  coloration: blue;
}

<div class="check">

  <h1>canine details</h1>
  
  <desk border="1" model="width: 90%;">
    <tr model="top: 50px;">
      <th model="font-size: 20px;" colspan="3">
        <p>Desk of Contents</p>
        <p model="font-size: 15px;">(click on the hyperlinks beneath to leap to desired part)</p>
      </th>
    </tr>
  </desk>
</div>