JSFiddle - React, Tailwind, and code Playground

HTML

<div id="left" style="float:left; width:100px; margin-right:10px;">
<input id="first" value="something">
</div>
<div id="right" style="margin-left:20px; float:left; width:200px;">
<input id="second" value="something">
<input id="third" value="something">
<input id="fourth" value="something">
</div>

CSS

input {width:100px;}

JavaScript

$(function() {

$("#right").focusin(function() {
      $( "#left" ).animate({
        width: "200px"
      }, 500 ); 
      $( "#right" ).animate({
        width: "100px"
      }, 500 );   
});
$("#right").focusout(function() {
      $("#left").animate({
        width: "100px"
      }, 500 ); 
      $("#right").animate({
        width: "200px"
      }, 500 ); 
});

})