JSFiddle - React, Tailwind, and code Playground

HTML

<main>
   <section>
      <wrapper>
         <div id="if-exists-remove-footer-styling">
            hey
         <div>
      </wrapper>
   </section>
</main>
       
       <div id="footer" class="top-margin">footer content</div>

CSS

.top-margin {
    margin-top:60px!important;
}
#footer {
    margin-top:0;background:red;
}

JavaScript

if($('#if-exists-remove-footer-styling').length >0) { 
        $("#footer").removeClass('top-margin')
    }