margin-collapse-vlr-035.xht
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>CSS Writing Modes Test: 'vertical-lr' and margin collapsing - left margin of a block collapses with left margin of its first child</title>
<link rel="author" title="GĂ©rard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" />
<link rel="help" href="http://www.w3.org/TR/css-writing-modes-3/#logical-direction-layout" title="7.4 Flow-Relative Mappings" />
<link rel="match" href="../reference/ref-filled-green-100px-square.xht" />
<!--
Test adapted from
http://test.csswg.org/suites/css2.1/nightly-unstable/html4/margin-collapse-017.htm
"
The margin collapsing rules apply exactly with the block-start margin substituted for the top margin and the block-end margin substituted for the bottom margin.
"
-->
<meta content="ahem image" name="flags" />
<meta name="assert" content="This test checks that, in a vertical-lr context, the left margin an in-flow block element collapses with its first in-flow block-level child's left margin if the element has no top border, no top padding, and the child has no clearance." />
<style type="text/css"><![CDATA[
div
{
font: 25px/1em Ahem;
height: 4em;
}
div#wrapper
{
background: red url("support/margin-collapse-2em-space-wm-vert.png") -1em top;
border-left: green solid 1em;
width: 3em;
writing-mode: vertical-lr;
}
div#parent
{
margin-left: 2em; /* block-start margin */
}
div#first-child
{
background-color: green;
margin-left: 2em; /* block-start margin of child */
width: 1em;
}
]]></style>
</head>
<body>
<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
<div id="wrapper">
<div id="parent">
<div id="first-child"></div>
</div>
</div>
</body>
</html>