Editing size of H5 and Paragraph Code Abbreviations

Site URL: https://www.shopmaisaguam.com/faqs

I am trying to edit the size of the text in my FAQ drop down menu, more specifically the question. I customized it to display the text using the font default for Heading 5 (H5), however, I can't seem to find where I can edit the size for Heading 5. The font editor only allows for edits up to Heading 4 (H4). How can I edit the size of Heading 5? Or is it even possible? 

Second, I understand the code abbreviation for headings begin with the letter and then the number (H1, H2, H3...) but what is the abbreviation for paragraphs? If it isn't possible to edit the size specs for Heading 5 maybe I'll just switch it to Paragraph 1 instead? 

Quote

<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>$(document).ready(function(){
    $('.markdown-block .sqs-block-content h5').addClass('ui-closed').css('cursor','pointer');
    $(".markdown-block .sqs-block-content h5").nextUntil("h5").slideToggle();
    $(".markdown-block .sqs-block-content h5").click(function() {
      $(this).nextUntil("h5").slideToggle();
      $(this).toggleClass('ui-closed ui-open');
    });
  });
  </script>

 

Insert Code Block in FAQs page > Paste below code

<style>
  .markdown-block h5 {
    font-size: 20px;
}
</style>

also, you can use this plugin to create FAQ Accordion, easy to install/customize heading/content