<!doctype HTML>
<html>
<meta charset="utf8">
<title>CSS Content Visibility: hidden container is not breakable (reference)</title>
<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">

<style>
#parent {
  width: 100px;
}
#container {
  border-top: solid green 50px;
  border-bottom: solid green 50px;
}
</style>

<div id="parent">
  <div id="container"></div>
</div>