JSFiddle - React, Tailwind, and code Playground
HTML
<input class="input1" type="button" value="input1" />
<input class="input2" type="button" value="input2" />
<div class="giftPopup shown"></div>
<div id="giftPopup"></div>
CSS
.giftPopup {display:none; background:red; border:2px solid black}
.giftPopup.shown {display:block; height:100px; width:100px; margin-top:50px}
JavaScript
$('.input1').click(function(){
$('#giftPopup').toggleClass('shown');
});