Re: [fxtf-drafts] filter should be defined to establish a containing block for fixed and absolutely positioned elements

For an HTML document, yes -- but the behavior in question (that we'd be mimicking here for filters) also involves the `<body>` element and the viewport.  Here's the spec text for the behaviors that Markus was referencing for `overflow` and `background`, with more concrete definitions/explanations:
https://www.w3.org/TR/css-overflow-3/#overflow-propagation
https://www.w3.org/TR/css-backgrounds-3/#body-background

-- 
GitHub Notification of comment by dholbert
Please view or discuss this issue at https://github.com/w3c/fxtf-drafts/issues/11#issuecomment-342978400 using your GitHub account

Received on Wednesday, 8 November 2017 22:12:58 UTC