Matéria definição

 <div class="accordion-div">

  <button class="accordion"><span class="faq__question-heading">Title1</span></button>

  <div class="panel">

    <p style="padding:18px 0;">description1</p>

  </div>

  <button class="accordion"><span class="faq__question-heading">Title2</span></button>

  <div class="panel">

    <p style="padding:18px 0;">description2</p>

  </div>

  <button class="accordion"><span class="faq__question-heading">Title3</span></button>

  <div class="panel">

    <p style="padding:18px 0;">description3</p>

  </div>

</div>