css/css-flexbox/empty-flex-box-and-margin-collapsing-ref.html - external/w3c/web-platform-tests - Git at Google

 <!DOCTYPE html>
 <style>
 div {
   background: green;
   height: 100px;
   width: 100px;
 }
 </style>
 <p>Test passes if there is a filled green square.</p>
 <div></div>
	<!DOCTYPE html>
	<style>
	div {
	background: green;
	height: 100px;
	width: 100px;
	}
	</style>
	<p>Test passes if there is a filled green square.</p>
	<div></div>