JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type="checkbox" checked>
    
    <label>This should be green</label>
  </form>

CSS

input::after
{
  content: "FAILED";
  margin-left: 2em;
}

input:checked::after
{
  content: "SUCCESS";
}

input + label 
{
  display: block;
  margin-top: 1em;
  background-color: red;
}

input:checked + label 
{
   background-color: green;
}