How to add title for div class container instead of using h3 tag

Question

I work on asp.net razor page i face issue i can't add title for div class container and title must be with top border 

exactly as field set and legend 

so how to apply title to be part from top border using html and css and jquery 

 <table style="border:1px solid black">
     <tr>
         <td style="width:300px;height:200px;">
             <div id="classesContainer">

                  <h2>Classes</h2> 
                 <div id="classesList" class="scrollable-list" style="padding-top:5px; margin-top:10px;width:300px;height:200px;">
                 </div>
             </div>
         </td>
        
     </tr>
 </table>

  <style>
      .scrollable-list {
          overflow-y: auto;
          max-height: 200px;
          width: 180px;
      }
</style>

and to fill div class container and classlist with data i use jquery below

$('#btnDisplay').click(function (event) {
     event.preventDefault();
     $('#classesContainer').attr('title', 'Classes');
   
     var dropdown = $('#accountclassname-select');
     dropdown.empty();
   
     $.ajax({
         url: '?handler=AccountClassName',
         type: "GET",
         dataType: "json",
         success: function (response) {
             $('#classesContainer').show();
             $('#classesList').html(''); // Clear existing classes
             $('#classesList').append('<input type="checkbox" id="checkall" class="chkall"  value="0" /><span> All </span> <br />');
          
             $.each(response, function (i, classes) {
                 var checkbox = $('<input type="checkbox" class="classCheckbox" value="' + classes.classAccountId + '" />');
                 var span = $('<span>' + classes.classAccountName + '</span>');
                 var listItem = $('<div></div>').append(checkbox, span);
                 $('#classesList').append(listItem);
             });
          
         }
     });
 });

so how to assign title for div classcontainer ?