JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="block" id="block">
<div id="box">
The box
</div>

JavaScript

var cbs = document.querySelectorAll('input[type=checkbox]');
for(var i = 0; i < cbs.length; i++) {
  cbs[i].addEventListener('change', function() {
    if(this.checked) {
      document.getElementById("box").style.backgroundColor = "red";
    } else {
      document.getElementById("box").style.backgroundColor = "transparent";
    }
  });
}