<!DOCTYPE html>
<meta charset="UTF-8">
<title>CSS Containment Test: 'contain: paint' and margin collapsing</title>
<link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
<link rel="help" href="https://www.w3.org/TR/css-contain-1/#containment-paint">
<link rel="match" href="reference/contain-paint-ifc-011-ref.html">
<meta content="This test checks that a block element with 'contain: paint' establishes a new block formatting context which is independent and separate from others. This causes margin collapsing to be ineffective among vertically-adjacent boxes. In this test, the top margin of parent boxes and top margin of their respective first in-flow child do not collapse. Also, in this test, the bottom margin of the last in-flow child of boxes and bottom margin of their respective parent boxes do not collapse." name="assert">
<style>
div
{
contain: paint;
margin: 30px 0px;
}
div#grand-grand-parent-orange
{
background-color: orange;
}
div#grand-parent-blue
{
background-color: blue;
}
div#parent-lime
{
background-color: lime;
}
div#collapse-through-child /* margin collapsing through element */
{
contain: none;
}
</style>
<p>Test passes if there are 5 horizontal stripes across the page in this order (from top to bottom): an orange stripe, a blue stripe, a bright green stripe, a blue stripe and then an orange stripe.
<div id="grand-grand-parent-orange">
<div id="grand-parent-blue">
<div id="parent-lime">
<div id="collapse-through-child"></div>
</div>
</div>
</div>
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