JSFiddle - React, Tailwind, and code Playground

HTML

<nav>
        <ul>
            <li><a href="/">home</a></li>
            <li><a href="/archive/">Archive</a></li>
            <li><a href="/about/">About</a></li>
            <li><a href="/contact/">Contact</a></li>
        </ul>
    </nav>

JavaScript

$("nav").click(function(){
    $("ul").toggle("slow", function() {
        var b = $("ul").css("display");
        console.log("ul display :"+b);// unfortunately,always returns block!
    });
    var b = $("ul").css("display");
    console.log("ul display :"+b);// unfortunately,always returns block!
});