24232 2014-01-08 05:59:33 +0000 The containing block of fixpos elements in the top layer shouldn't be the ICB 2014-01-10 16:36:58 +0000 1 1 1 Unclassified WebAppsWG Fullscreen unspecified All All RESOLVED FIXED P2 normal --- 1 falken annevk cpearce fantasai.bugs ian jackalmage mike public-webapps roc public-webapps-bugzilla oldest_to_newest 98120 0 falken 2014-01-08 05:59:33 +0000 The spec says the containing block of an element in the top layer is the initial containing block. However, this would mean elements with fixed positioning don't behave as such: they would be positioned relative to the document's origin rather than the viewport's. Instead, the containing block of fixpos elements should be the viewport, as normal. 98122 1 annevk 2014-01-08 09:10:49 +0000 Ian and Robert came up with this if I remember correctly. I'd like them to comment here first. 98123 2 annevk 2014-01-08 09:11:43 +0000 To be clear, comment 0 is about http://fullscreen.spec.whatwg.org/#rendering which should eventually move into CSS. 98180 3 roc 2014-01-09 04:03:59 +0000 I don't think it was me. However, viewport sounds right. 98200 4 annevk 2014-01-09 13:30:40 +0000 So, instead of "Its containing block is the initial containing block." we should have "If its position property computes to fixed, its containing block is the viewport, and the initial containing block otherwise." 98246 5 falken 2014-01-10 04:26:44 +0000 comment 4 looks good to me. 98262 6 annevk 2014-01-10 16:36:58 +0000 Thanks! https://github.com/whatwg/fullscreen/commit/d77e0158a10a2e1904ade9eac6d03531437c3ef7