JSFiddle - React, Tailwind, and code Playground
HTML
<div class="piece"></div>
<div class="piece"></div>
<p class="piece">Not 0</p>
CSS
div.piece {
z-index:1;
}
p.piece {
z-index:0;
}
JavaScript
$(".piece").each(function(){
var domElement = $( this ).get(0);
if($(this).css('z-index') != '0'){
alert("No. Element not at z-index:0: " + domElement.nodeName);
}else{
alert("Yes. Element at z-index:0 " + domElement.nodeName);
}
});