JSFiddle - React, Tailwind, and code Playground

HTML

<div id="fluffy"></div>
<div id="pepper" onclick="changeState()"></div>
<script type="text/javascript">
function changeState() {
    var fluffy = document.getElementById('fluffy');
    var divState = window.getComputedStyle(fluffy).display;

    if (divState == 'block') {
       fluffy.style.display = 'none';
    }
    else if (divState == 'none') {
       fluffy.style.display = 'block';
    } else {
       alert('test error message');
    }
}
</script>

CSS

#fluffy {
            height:200px;
            width:200px;
            background-color:yellow;
            display:block;
}
#pepper {
            height:200px;
            width:200px;
            background-color:green;
            display:block;
}