JSFiddle - React, Tailwind, and code Playground

HTML

<div id="hello">deepak sharma</div>
<input type="button" id="set10" value="set zindex = 10" />
<input type="button" id="set20" value="set zindex = 20" />
<input type="button" id="get" value="get" />

CSS

#hello
{
    position:relative;
}

JavaScript

$(function(){
    $("#set10").click(function(){
        $("#hello").css("z-index",10);        
    });
    $("#set20").click(function(){
        $("#hello").css("z-index",20);        
    });
    $("#get").click(function(){
        alert($("#hello").css("z-index"));
    });
});