JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
<div class="formhead">Heading Title 1</div>
<div class="fieldleft">
    <label for="specificinput">Input Title</label>
    <input type="text" class="forminput" id="specificinput">
</div>
<div class="fieldleft">
    <label for="specificinput">Input Title</label>
    <input type="text" class="forminput" id="specificinput">
</div>
</div>
</fieldset>

<fieldset>
<div class="formhead">Heading Title 2</div>
<div class="fieldleft">
    <label for="specificinput">Input Title</label>
    <input type="text" class="forminput" id="specificinput">
</div>
<div class="fieldleft">
    <label for="specificinput">Input Title</label>
    <input type="text" class="forminput" id="specificinput">
</div>
</div>
</fieldset>

CSS

.bluebg { background: cyan; }

JavaScript

$('input.forminput').bind('focus blur', function () {
    $(this).closest('fieldset').find('.formhead').toggleClass('bluebg');
});