JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <div>
        <input/>
        <input/>
    </div>
    <div>
        <input/>
        <input/>
    </div>
</form>

CSS

div { width:300px; padding: 5px 15px; border-radius: 5px; margin: 3px auto;}
input { width: 145px; }

.curFocus {
    border: 1px solid #00f; background: yellow;  
}

JavaScript

$('form > div').delegate('input', 'focus', function() {
    $(this).closest('div').addClass('curFocus');
}).delegate('input', 'blur', function() {
    $(this).closest('div').removeClass('curfocus');    
});