JSFiddle - React, Tailwind, and code Playground

HTML

<div id="output"></div>

CSS

div#output {
    background-color: #AAA;
    width: 200px;
    height: 50px;
    text-align: center;
    font-size: 40px;
}
div#output.ctrlKey {
    background-color: #0F0;
}
div#output.noCtrlKey {
    background-color: #F00;
}

JavaScript

var o = document.getElementById('output');

o.addEventListener('click', function(e) {
    this.innerHTML = e.ctrlKey;
    if (e.ctrlKey)
        this.className = 'ctrlKey';
    else
        this.className = 'noCtrlKey';
});

document.addEventListener('keyup', function(e) {
    if (e.key.toLowerCase() == 'arrowright')
    {
        o.click(e);
        return false;
    }
});