This is the "Checkbox Hack".

dabblet.css

/* Checkbox Hack */

input[type=checkbox] {
  position: absolute;
   top: -9999px;
   left: -9999px;
 
}
label { 
/*  -webkit-appearance: push-button;
  -moz-appearance: button; 
  display: inline-block;
  margin: 60px 0 10px 0;
*/  cursor: pointer;
}

/* Default State */
div {
   background: green;
   width: 400px;
   height: 100px;
   line-height: 100px;
   color: white;
   text-align: center;
   color:#333;
   background: #FFF;border: solid 3px #CCC;
}

/* Toggled State */
input[type=checkbox]:checked ~ div {
   background: #ccc;border: solid 3px #999;
}

dabblet.html

<label for="toggle-1">
<input type="checkbox" id="toggle-1">
<div>I'm controlled by toggle. No JavaScript!</div>
</label>

settings.json

{"view":"split-vertical","fontsize":"100","seethrough":"","prefixfree":"1","page":"all"}