<div class="accordion">
     <div class="panel">
       <div class="panel-header">
         <h1>HTML</h1>
       </div>
       <div class="panel-body">
         <p>helllo</p>
        </div>
      </div>
<div class="panel">
       <div class="panel-header">
         <h1>HTML</h1>
       </div>
       <div class="panel-body">
         <p>helllo</p>
        </div>
      </div>
<div class="panel">
       <div class="panel-header">
         <h1>HTML</h1>
       </div>
       <div class="panel-body">
         <p>helllo</p>
        </div>
      </div>  
</div>
.accordion {
  width: 450px;
  margin: auto;
}
.panel {
  border: 1px solid #222;
  padding: 5px;
}
.panel-body {
  display: none;
}
.panel-header h1:hover {
  text-decoration: underline;
  cursor: pointer;
}
$(".panel-header h1").on('click', function(){
  //$(".panel-body").toggle();
  $(this).parent().siblings('.panel-body').toggle();
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js