15:56:35 RRSAgent has joined #css 15:56:40 logging to https://www.w3.org/2026/07/01-css-irc 15:56:41 RRSAgent, make logs Public 15:56:42 Meeting: Cascading Style Sheets (CSS) Working Group Teleconference 15:57:36 PaulG has joined #css 15:59:12 ydaniv has joined #css 15:59:41 vitorroriz has joined #css 15:59:48 present+ 16:00:03 present+ 16:00:10 kbabbitt has joined #css 16:00:26 present+ 16:00:31 present+ 16:00:50 present+ 16:01:03 hoch has joined #css 16:01:23 present+ 16:01:29 present+ 16:01:32 present+ 16:01:33 present+ 16:01:36 present+ 16:01:41 kizu has joined #css 16:01:46 davidjmarland has joined #css 16:01:53 present+ 16:01:55 masonf has joined #css 16:01:57 noamr has joined #css 16:02:03 present+ 16:02:12 alisonmaher has joined #css 16:02:12 present+ 16:02:15 schenney has joined #css 16:02:17 present+ 16:02:18 present+ 16:02:53 github-bot, topic https://github.com/w3c/csswg-drafts/issues/13816 16:02:53 Topic: [css-overflow] Scroll direction of unicode-bidi: plaintext. 16:02:53 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/13816 16:02:56 present+ 16:03:04 present+ 16:03:21 present+ 16:03:25 lea has joined #css 16:03:54 Estelle has joined #css 16:04:09 github-bot: none 16:04:09 JoshT, Sorry, I don't understand that command. Try 'help'. 16:04:09 github: none 16:04:14 I think Emilio said he might only make it to the IRC channel and left comments on Github 16:04:21 github-bot, topic https://github.com/w3c/csswg-drafts/issues/13652 16:04:21 Topic: [css-sizing] "behaves as auto" needs clarifications 16:04:21 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/13652 16:04:42 present+ 16:04:49 fantasai: when we drafted the auto stuff, we were handy wavy about it 16:04:58 ... it behaves as auto in most but not all cases 16:05:14 smfr has joined #css 16:05:14 ... interesting case brought up is margin collapsing 16:05:27 q+ 16:05:32 ... box with margin height, its last child can collapse with its own margin and the following sibling 16:05:48 ... but if it's not auto, like length or %, then margin collapsing does not happen 16:06:06 present+ 16:06:10 ... so the auto behaviour gets set if % is resolvavle because the container has a definite height 16:06:33 ... spec says that when the % can't resolve like in block layout, the height is calc in a way that behaves as auto 16:06:43 ... but spec checks computed value which is %, not auto 16:06:56 ... so the spec says you are not supposed to collapse the margins 16:07:05 cepan has joined #css 16:07:13 ... but since written, there are new keywords so what is the right thing to do in various cases 16:07:32 ... brings up question that some impl include margin collapsing and some check the computed value specifically 16:07:56 ... so on one side, people says it should behave as auto in all aspects. on the other side, should it also unpack margin collapsing 16:08:01 q+ 16:08:04 ack TabAtkins 16:08:10 fantasai has joined #css 16:08:17 TabAtkins: comment in issue asks for concrete proposal 16:08:27 ... right now it doesn't actually propose what is changing 16:08:32 ... and asks for some examples 16:08:47 ... i do not support a change now before more concrete pros, suggestions and what this means for pages 16:09:00 fantasai: I filed this originally to flesh this out a bit more 16:09:02 Present+ 16:09:09 ... oriol and ??? got into this case of margin collapsing 16:09:21 TabAtkins: in that case, I don't know what you want to edit 16:09:26 ... if that's only one aspect 16:09:36 fantasai: they're all probably independently editable 16:09:37 s/???/anne/ 16:09:57 ... i can't remember what other side effects there are for auto 16:09:58 dholbert has joined #css 16:10:04 present+] 16:10:07 ack oriol 16:10:07 present+ 16:10:19 oriol: I think that if we say something behaves as auto, then behaviour should be ?? 16:10:35 ... we could add dependencies on computed values, but I do not see agreement on that here 16:11:05 s/??/as close to auto as we can/ 16:11:08 ... we should only add the auto behaviour when there's a good reason 16:11:19 fwiw, I got confused by the spec wording on this while working on Ladybird once. 16:11:22 ... this allows margins to collapse as auto. it's only webkit that checks the computed value 16:11:37 https://github.com/w3c/csswg-drafts/issues/12218 16:11:41 ... several impl seem to collapse margins like webkit but there are some cases quite non-sensical 16:11:47 ... explained in linked issue 16:11:53 ... I think Blink's model is better 16:12:11 ack fantasai 16:12:11 fantasai, you wanted to distinguish what's obvious from spec terminology != what's obvious for authoring 16:12:12 ... even then it's only webkit behaving in this way. I think it should allow collapsing margins as auto 16:12:20 q+ 16:12:28 fantasai: so I want to make a distinction for what makes sense based on what's in the spec 16:12:43 ... the original reason for this behavuiur is that % are not resolvable 16:12:56 ... we just needed some term to hook onto this idea 16:13:06 ... would like to ask what will the author most likely expect to happen 16:13:23 ... if most obvious is to collapse margins with % heights, then we should align on that 16:13:25 q+ 16:13:29 ... if it's not, then we should do the other thing 16:13:29 I think my point is still just that this issue doesn't actually contain any proposals (but there's an *implied* proposal about margin collapsing, which has a proposed WPT change to match) 16:13:43 astearns: web compat is likely a good reason not to follow auto if impl are not following spec 16:13:56 ... but also, does anyone know what is the test case that anna added is checking 16:14:08 s/anna/anne 16:14:18 oriol: i think originally came from a test cases I added 16:14:24 fantasai: test case about stretch keyword 16:14:38 ... in most cases, it's treated as implicit size and margins will not collapser 16:14:52 ... if it has a child, the margin will not collapse as it's not expected to match 16:15:08 Currently all browsers pass the test in its current form https://wpt.fyi/results/css/css-sizing/margin-collapse-with-indefinite-block-size-005.html?label=master&label=experimental&aligned 16:15:12 ... if the container that the stretched item is in has a height, we run into this issue of whether to collapse 16:15:20 ... for stretch, the size of the container could be resolved 16:15:38 kurt has joined #css 16:15:43 ... but when you have explicit height, the margins collpse, and when you don't, the margins don't collapse 16:15:49 ... that's confusing 16:15:50 ack oriol 16:15:54 ack astearns 16:16:11 oriol: for author expectations, when the spec is checking this, it's making sure margins only collapse when they align 16:16:13 *Is* this issue specifically about the margin-collapse issue? Elika stated it was about several things. 16:16:26 ... so you can make the bottom margin of last item and parent collapse 16:16:36 ... if parent has explicit size, you can't guarantee that you can do that 16:16:41 It was an issue about "we have some wording that needs tightening up here". And the margin collapsing issue is the main one that we have identified. 16:16:57 ... if this case, a % behaves as auto for sizing purposes, then margin collapsing purposes is the same 16:17:10 ... I think it makes sense to allow margin collapsing in all cases 16:17:22 fantasai: if you pick 40px as the size of your box, we still don't collapse the content 16:17:34 oriol: true. earlier linked to issue about it. 16:17:47 ... but point is whether you guarantee it adapts to content 16:18:00 ... % behaves as auto always, so size will always ???? contents 16:18:08 fantasai: depends on where you use the box 16:18:38 ... if someone sizes margins and padding with some assumption about whether margins collapse and then put it in container with auto height, it may or may not collapse, it's confusing 16:18:45 ... could cause unexpected breakage 16:18:57 ... if you set it to stretch or 100%, you're expecting something different to happen 16:19:25 ... for behaviour to change depending on what you put it into, it's confusing. if you want the other bhaviour,. you can just ask for it 16:19:45 ... if you are expecting margins to collapse sometimes and not other times, that's not a winning thing 16:20:06 ... depending on the spacing you want, you'd have to compensate for the collapsing or not collapsing 16:20:28 astearns: as Ian and TabAtkins suggested, we can take this back to the issue with one concrete example 16:20:44 ... we can have an idea of what we want to resolve on before this comes back onto the agenda 16:20:56 github-bot, topic https://github.com/w3c/csswg-drafts/issues/11801 16:20:57 Topic: [css-navigation-1] Add pseudo-class selector to target the element that initiated the outgoing navigation 16:20:57 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/11801 16:21:09 noamr: issue that was open for a while 16:21:19 ... we wanted to address with css-nav-1 spec 16:21:34 ... quite ready on it's own. to select a link that triggers a navigation 16:21:35 dholbert has joined #css 16:21:49 ... unlike active pseudo, it stays on 16:21:50 Like :active in IE5! 16:22:13 ... so we defined in css-nav-1 as trigger-link. we define exact processing model of when it starts and stops being active 16:22:26 ... we found about css-nav that it's a reflection of the Web Navigation API 16:22:34 ... has concept of source-element. 16:22:41 ... not sure if that was the best name 16:22:48 ... can be a link, a form or submit button 16:22:54 q+ 16:22:58 ... things that trigger a navigation 16:22:58 q+ 16:23:14 ... trigger-link is both the source element and the link 16:23:18 q+ 16:23:21 ... could be confusing otherwise with forms 16:23:32 ... could say we have a navigation trigger element that also includes forms 16:23:42 ... current case is a pseudo class called trigger-link 16:23:48 ... activated on link you click 16:23:54 ... stops when navigation is done 16:24:04 q- 16:24:07 ... when you swap to the new document 16:24:27 TabAtkins: echoing discussion, odd specialised just to links when there are forms doing nav 16:24:28 ack TabAtkins 16:24:38 ... assuming more general pseudo class, this is just adding 'a' 16:24:41 +1 16:24:57 ... could we just let people use the tag name in the selector to say which they want to match on? 16:25:04 Don't image maps also have links in them? 16:25:19 web components and aria-* components will probably like to support this as well 16:25:21 noamr: not great in my opinion, but could be wrong. we can change that 16:25:43 TabAtkins: concern is just in general it's not great to encourage authors to use links when they should use a form 16:25:51 +1 16:25:54 ... if these touch both cases, they should work on both cases 16:25:55 CameronPsychpsyo, image maps have elements these days -- HTML4 had a feature that allowed them to use as well but it got removed in HTML5 due to only one browser implementing it. 16:26:17 astearns: have maybe terrible idea. if we need something different than active for the lifecycle, then maybe this could be a parameter on :active 16:26:23 Yes, but can have an href to link to elsewhere when clicked. 16:26:25 ack astearns 16:26:26 ntim has joined #css 16:26:34 fantasai: had the same concerns as TabAtkins 16:26:44 ... think a more general definition is better 16:26:46 present+ 16:27:04 ... for more general name, could be navigation-source, connecting to the source term 16:27:08 noamr: sounds good to me 16:27:22 ... i was nervous about trigger because we also have nav trigger 16:27:36 navigation referrer? 16:27:42 bramus: but you can have source and destination so having source here could confusing 16:27:48 noamr: still related 16:28:00 fantasai: what happens if you have a link that navs to a different part of the page? 16:28:12 noamr: it will still activate and pseudo will still be active 16:28:23 ... as long as Navigation API is going, it will apply 16:28:29 I think (somewhat agreeing with Bramus) that some people might see the "source" as the page you're navigating from rather than the element that caused that page to navigate. 16:28:39 ... because it's very quick, effect might not be different from activ 16:28:54 fantasai: old versions of IE have more persistent versions of :active 16:28:56 q? 16:29:04 noamr: will be active until animation is done 16:29:10 ... same with smooth scroll 16:29:17 q+ 16:29:20 ... as long as the spinner goes, this will also be active 16:29:25 fantasai: in general, a good idea 16:29:30 ack fantasai 16:29:32 ack bramus 16:29:45 bramus: hearing +1 on the ask for a broader selector 16:30:00 ... if we could have that, I'd be very happy as that was the original request 16:30:09 ... then you just prepend an element selector 16:30:30 ... for name, dbaron said he also agrees people might confuse source with source vs destination 16:30:53 ... suggested in issue :navigation-trigger to make it clear it's the element and not the 'from' page 16:31:10 fantasai: the source element API is already using that term so reflecting that makes sense 16:31:25 ... and you can't just select the page with a selector so there's no room for confusion here 16:31:43 noamr: we could just not use 'source' in other places and say 'from' in those nav to and from use cases 16:32:02 astearns: and the Navigation APi uses 'source' for this concept? 16:32:04 noamr: yes 16:32:16 astearns: any concerns about adding this regardless of the name? 16:32:43 ... given everyone seems OK with it, shall we give a provisional name of :navigation-source? 16:32:53 ... or :nav-source? 16:33:07 noamr: i like the shorter one because it makes it feel like an element 16:33:13 I still like referrer but it's harder to spell? 16:33:22 ... if we do something that is a navigation source, we can distinguish from a nav source 16:33:29 bramus: I'm leaning to full version 16:33:29 prefers to avoid abbreviations 16:33:44 fantasai: can we have nav-up, nav-down? 16:34:07 ... would be consistent with that and nav is shorter to write and we have precident 16:34:14 I prefer not abbreviating in this case 16:34:18 astearns: precedent in specs or implementations? 16:34:23 i do prefer abbreviating 16:34:39 florian: I recall that nav-up and nav-down are not interoperable 16:35:01 astearns: at least on IRC, people are on both sides 16:35:09 TabAtkins: and HTML spec has nav element 16:35:19 happy with nav 16:35:24 astearns: resolve on adding :nav-source in short form? 16:35:36 :navigation-source-trigger-element 16:35:40 fantasai: I'm ok with either or doing a Twitter poll 16:35:57 +1 on short form 16:35:59 :navigation-starting-element 16:36:06 "source" or "src"? 16:36:08 PROPOSED: add :nav-source pseudo for this use case 16:36:16 source. src feels like a URL of sorts 16:36:23 lol we spell out "source" everywhere else in css 16:36:32 RESOLVED: add :nav-source pseudo for this use case 16:36:37 i'd rather abbreviate source than nav 16:36:43 people discuss src or source 16:36:44 PROPOSED: Add :nav-source to select element that initiates navigation (whether link or not) 16:36:45 sauce 16:36:55 :navigation-src 16:37:08 RESOLVED: Applies not just to links 16:37:26 github-bot, topic https://github.com/w3c/csswg-drafts/issues/14062 16:37:27 Topic: [css-anchor-position-1] Add flip-self-inline/flip-self-block keywords 16:37:27 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/14062 16:37:46 astearns: Might be the shortest issue ever! 16:37:53 +1 to the keywords 16:38:03 fantasai: we have flip-inline and flip-block which use writing mode of the container 16:38:14 ... we have use cases to have the writing mode of the element itself 16:38:22 astearns: both self and the parent? 16:38:25 fantasai: yes 16:38:39 ... we should be consistent 16:38:51 ... and make them the keyword that you use for the custom select dropdown 16:39:02 astearns: any concerns? 16:39:17 PROPOSED: add flip-self-inline and flip-self-block 16:39:35 RESOLVED: add flip-self-inline and flip-self-block to position-try 16:39:40 position-try-fallbacks 16:39:47 RESOLVED: Use these values for ::picker(select) 16:40:10 github-bot, topic https://github.com/w3c/csswg-drafts/issues/13853#issuecomment-4820636728 16:40:10 Topic: [web-animations] How/when do the "rangeStart/rangeEnd" attributes the Animation interface get evaluated 16:40:10 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/13853 16:40:52 weinig: issue is that in the animations API in the JS API, there are places where you can set values 16:40:59 ...the setters have been defined to take strings 16:41:12 ... but the spec says 'parse this as...' and then a CSS property 16:41:37 ... in this case, the issue with range-start is that it takes what it should parse, and animation-range-end allows a length-percentage with any number 16:41:43 ... you can have length relative units 16:41:50 ... there's no spec on how to resolve those units 16:41:59 ... it's not happening during the style resolution 16:42:13 ... in other places, there's an API that takes a string and parses it as a CSS construct 16:42:29 ... normally we limit it to absolute units because we don't have a way to resolve relative units 16:42:57 ... in this bug it's about range-end, but we can take the same idea to other cases and limit to absolute length units and %. % are ok because they resolve later 16:43:01 I'm fine with this 16:43:05 sgtm 16:43:14 dholbert has joined #css 16:43:22 astearns: is it possible to define some way to resolve %? 16:43:34 weinig: % are not an issue. it's just relative units 16:43:46 astearns: so can we just pick something to resolve against like the root? 16:43:54 weinig: there are other options we could takw 16:44:00 q+ 16:44:02 ... one is to treat it like media queries 16:44:18 ... say that relative units resolve against the initial style. could be different to the root 16:44:38 ... could say the units resolve against the target element of anim if it exists 16:44:48 ... then need to define what happens if target is null 16:44:57 ... and we need to pay the sync style resolution cost 16:45:11 ... or alt, we could define alternative time that these values get resolved against an element 16:45:16 ... i think they're all complicated 16:45:25 ... someone would need to figure out the tradeoffs 16:45:31 ... right now not implementable 16:45:43 ... want something implementable in a uniform way 16:46:07 SGTM, until we define this properly 16:46:12 ... or maybe in future we'll have a generic way in JS to say 'given this element and unit, give me the computed px values' 16:46:19 ... someone in bug says this makes it useless 16:46:31 ... don't know if they were thinking if % weren't allowed 16:47:02 ydaniv: [that was me]. it is limiting, but it's OK to patch this now and spec it later 16:47:34 astearns: I agree and I'm fine, but if there is something that would be better for authors where we can arbitrarily pick an element without author choice, it might be better to do that than only have absolute units 16:47:52 ... if we do only absolute units now, we'll need an opt in to get the better behaviour 16:48:10 weinig: we can just do a parse error for relative units for now, and then not have a parse error in the future 16:48:10 ack TabAtkins 16:48:19 TabAtkins: I agree with sam. don't want to resolve on root element 16:48:28 ... would rather make it parse-time invalid now 16:48:31 +1 to TabAtkins and weinig 16:48:44 weinig: my proposal is for both the string form and type CSS form 16:48:50 yeah there shoudln't be any difference between those two 16:48:59 ... you can do a typed value that is an em value, so we have to treat them the same here 16:49:53 PROPOSED: make it a parse error to set string values or typed CSSOM values that don't use absolute length units or percentages 16:50:53 weinig: one other clarificatio.n also precludes things like var, sibling-index() and anything that requires an element to resolve 16:51:04 sgtm 16:51:14 We can always relax restrictions once we figure out what's the best thing to do 16:51:14 ... but the implication is we're excluding anything that requires an element context 16:51:31 PROPOSED: make it a parse error to set string values or typed CSSOM values that require an element to resolve 16:51:40 RESOLVED: make it a parse error to set string values or typed CSSOM values that require an element to resolve 16:51:56 weinig: I've filed a bunch of issues like this. should I turn them all into a single issue that we can resolve on later? 16:52:04 ... or should we go through them one by one? 16:52:14 astearns: I'm fine with that if they're all basically the same decision 16:52:22 ... we can even make it an async proposal 16:52:52 github-bot, topic https://github.com/w3c/csswg-drafts/issues/13904 16:52:53 Topic: [css-view-transitions] [cssom] Inheritance of non-existing pseudo-elements. 16:52:53 OK, I'll post this discussion to https://github.com/w3c/csswg-drafts/issues/13904 16:53:19 TabAtkins: emilio pointed out that we have a WPT that expects a non-existant vt element to inherit from its non-existent parent 16:53:32 ... because vt pseudos aren't creating but you're asking for the computed style 16:53:52 ... emilio suggests that we inherit from the existing element rather than assuming a non-existent tree 16:54:10 ... the dev who did this had a crash and so he fixed it in a way and doesn't have opinions on which way it should go 16:54:15 ... I also agree 16:54:31 ... we probably should not be making assumptions about the state of a tree that doesn't exist 16:54:40 ... I suggest we take emilio 's suggestion 16:54:58 ... just say it's inheriting from the originating element 16:55:15 sgtm 16:55:35 fantasai: so this is only while they don't exist? and then when we have a tree, do usual behaviour? 16:55:39 TabAtkins: yes? 16:55:44 s/yes?/yes/ 16:56:00 el.gCS("::foo") 16:56:00 TabAtkins: and there is always in the query an originating element to look at 16:56:14 fantasai: there was a term for ultimate originating element 16:56:18 TabAtkins: yes 16:56:56 PROPOSED: non existing pseudo-elements are considered to inherit from their ultimate originating element if you query the computed style 16:57:19 astearns: any suggestions or objections? 16:57:28 RESOLVED: non existing pseudo-elements are considered to inherit from their ultimate originating element if you query the computed style 16:57:36 astearns: do we have any other situations like this? 16:57:55 TabAtkins: you can't ask for an element that might not exist. it's only pseudos where this can happen 16:58:00 "A non-existent pseudo element falls in the forest. what style does it have?" 16:58:27 topic: end 17:00:24 zakim, end meeting 17:00:24 As of this point the attendees have been ChrisL, JoshT, ydaniv, JohnJansen, rachelandrew, CameronPsychpsyo, hoch, vitorroriz, kbabbitt, bramus, kizu, masonf, noamr, alisonmaher, 17:00:27 ... davidjmarland, oriol, romain, fantasai, lea, PaulG, dbaron, ], dholbert, ntim 17:00:27 RRSAgent, please draft minutes v2 17:00:29 I have made the request to generate https://www.w3.org/2026/07/01-css-minutes.html Zakim 17:00:36 I am happy to have been of service, astearns; please remember to excuse RRSAgent. Goodbye 17:00:36 Zakim has left #css 17:29:26 sbender has joined #css 19:16:23 sbender_ has joined #css 20:33:52 sbender has joined #css 21:00:07 github-bot has joined #css