JSFiddle - React, Tailwind, and code Playground

HTML

<div id="ifYes" style="display:none;margin-top:3%;">If yes, explain:</div>

JavaScript

function yesnoCheck() {
        if (document.getElementById('yesCheck').checked) {
           document.getElementById('ifYes').style.display = 'block';
        } else {
           document.getElementById('ifYes').style.display = 'none';
        }
    }