I built a thing this week (with the help of Antigravity): a CSS Typed OM polyfill.

It currently passes 12588 of WPT's 12942 CSS Typed OM test, which is more than any browser!

https://github.com/bramus/css-typed-om-polyfill

New in Chrome DevTools in Chrome 151 (which goes stable mid July):

The specificity bubble can now show you a breakdown of how the specificity was calculated.

Big thank you and congrats to januschka.com for contributing this to Chromium 👏

@marcthiele “I love the shape of Bramus’ talk. […] It goes looking for the edge on purpose, shows you the failures along the way, and comes back with both a real tool and a grin. That is about as beyond tellerrand as a talk about a CSS specification can get. ;)”

Thank you, Marc.

On the Beyond Tellerrand blog you can find an accompanying write-up, written by conference organizer @marcthiele

https://beyondtellerrand.com/blog/btconf-dusseldorf-2026-video-bramus-van-damme

I am moved by the kind words Marc had to say about my talk. It proves, again, that he is one of the kindest and warmest persons I have ever met.

RE: https://mastodon.social/@btconf/116843238015514133

It’s video release week!

After the recording from All Day Hey and CSS Day before, the recording from Beyond Tellerrand is now available too.

While the talk is technically the same, the flow of it as well as its contents are quite different from those other renditions, so you might want to give this one a watch as well.

With #GoogleIOConnect Berlin just last week, my pre-summer conference season has come to a close.

In 2 months I did 4 Meetups, 5 Conferences, and 1 Team Summit … while doing some _actual work_ in between 🫨

This week I’m tying up some loose ends, and after that I’ll be taking some time off 🏝️

#ChromeDevRel

👀 http://crrev.com/c/7952977

“Support colorspace and alpha attributes on <input type=color>”

Available for testing behind the Experimental Web Platform Features flag in Chrome Canary, starting tomorrow.

New Blog Post: “Do Websites Need to Function Exactly the Same on Every Platform?”

https://www.bram.us/2026/06/21/do-websites-need-to-function-exactly-the-same-on-every-platform/

(Betteridge’s Law of Headlines applies)

New Blog Post:

View Transitions: Should you use the new `attr()` or `match-element` for the `view-transition-name`?

Well … It Depends™

https://www.bram.us/2026/06/19/view-transition-name-attr-or-match-element/

New demo: Animated CSS Grid Layout.

https://codepen.io/bramus/pen/ogBYjgm

Here’s the thing, though: No View Transitions. Heck, no JS at all!

Instead, it uses Anchor Positioning to anchor the cell contents to the cell. Then, CSS transitions are used to animate the contents to their new location as the grid re-layouts.

Here's that calc-size() article @argyleink mentioned just now.

https://developer.chrome.com/docs/css-ui/animate-to-height-auto

Animate to `height: auto` is possible nowadays!

#CSSDay

Excited for this talk by @argyleink.

I got a sneak peek yesterday, and this is gonna be gooooodddd! 🤩

#CSSDay

Here's that issue about overscroll areas that @Una just mentioned.

https://github.com/openui/open-ui/issues/1457

I feel like they should probably be defined in CSS. See the issue for my reasoning here.

#CSSDay #OverscrollAreas #OpenUI

@nomster We want your feedback! Write a blogpost, send me a message, etc.

Very eager to hear what your use cases and needs are here 😊

At #CSSDay, we (@nomster and I) did a first public pitch of something we are currently prototyping: a way to add styles based on the active navigation.

Handy for View Transitions, and a few other things.

https://drafts.csswg.org/css-navigation-1/ is a WIP spec, with some bits implemented (behind a flag) in Chrome.

There, I fixed it:

:root {
--masonry: grid-lanes;
}

.container {
display: var(--masonry);
}

#CSSDay #GridLanes #Masonry

YES, Dark Mode Toggles _should_ be a browser feature.

I wrote about this before: https://brm.us/dark-mode-override

Find the link to the Chrome Bug in the post, and hit the star next to it to "upvote" the bug.

#cssday

If you liked Jelle's talk and want to revisit, I have a small section on value processing on my blog (as part of a post on IACVT): https://brm.us/value-processing

#CSSDay

CSS Day, day 1. #cssday

CSS DevRel, The Reunion. #CSSDay #ChromeDevRel

Caption: @argyleink, @Una, and I.

#cssday, day 0.

Tomorrow's gonna be a day of travelling + some meetings at the NL office + setting up our booth at the venue + pre-conf speaker dinner + a final rehearsal (and some last minute changes to the deck)

On Thursday the it's showtime 🤩 #cssday

Ready for this! #cssday

https://cssday.nl/speakers.html#bramus

RE: https://mastodon.social/@cssday/116685419264339242

👀

/ping @sarajw, for your #CSSDay talk 😉

👀 https://github.com/WebKit/WebKit/pull/66078

“[css-images] Add support for light-dark(<image>, <image>)”

✅ Firefox 150
✅ Chrome 150 (Jun 17)
🔜 Safari

Find all info about light-dark with images right here: https://www.bram.us/2026/03/19/more-easy-light-dark-mode-switching-light-dark-is-about-to-support-images/

👀 https://chromium-review.googlesource.com/7853759

“[flex-balance] Enable by default.”

Chrome 150, let’s go! 🎉

@Una I might need to recount, but I think we cover 34 (!!) new #CSS and Web UI features in 45 minutes in this talk.

Every demo shown in the talk has a link, and there's also a ton of links to articles and explainers included throughout.

And yes, we also show compat tables and baseline indicators.

Here's the recording of this year's “What's new in Web UI” talk @Una and I gave at Google I/O earlier this week.

https://youtu.be/uT7MVcCQ4rw

Very happy with how it went, and I think you might find it useful, so give it a watch 😊

#ChromeDevRel #GoogleIO

Half an hour to go before @Una and I take the stage at #GoogleIO to give you an update on CSS and Web UI.

Tune in here: https://io.google/2026/explore/pa-keynote-10

#ChromeDevRel