I'm just trying to understand the default stylesheet for Chrome.
If you have this html:
<body><h1>Hello</h1></body>
By default the <body> tag has a margin of 8px, and the <h1> tag has a default -webkit-margin-before of 0.67 em, which comes to 21.44px. Why then does the <h1> tag appear to ignore the 21.44px margin? Margin collapse rules should take the larger of the two margins.
Thanks!
In quirks mode, margin collapsing behaves differently in a variety of situations. In your example, the default top margin of any first child of body that has default margins, such as p or h1, will be ignored. I believe Chrome implements this behavior via the -webkit-margin-collapse property (as mentioned in your title); Firefox instead zeroes out the top margin of most body > :-moz-first-node elements (see quirk.css).
You'll see the expected behavior when you include a DOCTYPE.