JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://code.jquery.com/ui/1.9.0/themes/base/jquery-ui.css">
<script src="http://code.jquery.com/ui/1.9.0/jquery-ui.js"></script>
<div class="div">
    <input type="text" />
     <input type="text" /> 
     <input type="text" /> 
</div>

 <input type="text" class="b"/>

CSS

.disabled
{
    background-color: orange;
}

JavaScript

$('.div input[type="text"]').on('focus', function(){
    $('.b').prop('disabled', true).addClass('disabled');
    
}).on('blur', function(){
     $('.b').prop('disabled', false).removeClass('disabled'); 
});