JSFiddle - React, Tailwind, and code Playground

HTML

<script
  src="https://code.jquery.com/jquery-3.2.1.min.js"
  integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4="
  crossorigin="anonymous"></script>
  
<form id="loginCard" action="#">
  <input type="text" value="" name="one" />
   <input type="text" value="xxxxxx" name="some" />
  <input type="text" value="" name="two" />
  <input type="text" value="myVal" name="three" />
</form>

CSS

input.error { border: 1px solid red; }

JavaScript

/* jQuery("#loginCard").find('input').each(function (){ 
    if($(this).val()==""){
       $(this).addClass("error"); 
    }
}); */