JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">
    
    <div class="one">one</div>
    <div class="two">two</div>
   
</div>

CSS

.main {
    width:500px;
    height:100px;
}
.one {
    width:0px;
    display:none;
    background-color:#f00;
}
.two {
    width:200px;
    display:inline-block;
    background-color:#0c0;
}

JavaScript

$(".two").click(function(){ return $(".one").css("display","inline-block").animate({ width:"200px" }); });