FeedCity

Back in January 2022, I wrote about an exciting new CSS Working Group decision: a function to detect at-rule support using @supports at-rule(@keyword). Fast forward to today, and the CSS Conditional Rules Module Level 5 specification has solidified how this feature works and Chromium (Chrome, Edge, etc.) is about to ship it in Chromium 148!

Back in January 2022, I wrote about an exciting new CSS Working Group decision: a function to detect at-rule support using @supports at-rule(@keyword). Fast forward to today, and the CSS Conditional Rules Module Level 5 specification has solidified how this feature works and Chromium (Chrome, Edge, etc.) is about to ship it in Chromium 148!

New in Chromium 148: detect at-rule support in CSS with `@supports at-rule(@keyword)`

https://www.bram.us/2026/03/15/at-rule/

Chrome 148 is currently available on the Canary and Dev release channels. It goes stable at the end of April.

Get noodled.

RE: https://mastodon.world/@heypresents/116222571128090421

“Curiosity breeds Discovery”

I spend a fair bit of time playing with View Transitions, and bending it in all sorts of ways.

This talk compiles my insights from building some of the more wild things with VTs.

See you at All Day Hey!?

(Expect a lot of code getting thrown your way!)

Other takeaways are:

- Damn, that was fast!
- We need a way in DevTools/the web to be notified of style changes (hello, brm.us/style-observer!)
- We need a Element.getAnchor() JS method.
- The "remembered scroll offsets" are a PITA.

So. Anchor Positioning and DevTools …

I sat together with The Hype™ tonight and this is what we built in 2 hours.

Main takeaway from this experiment is that it still requires a “Subject Matter Expert” (in this case: me) to build this, instructing The Hype™ what to do (and sometimes how to do it).

Introducing `view-transitions-mock`: A non-visual Polyfill for Same-Document View Transitions

https://www.bram.us/2026/03/11/view-transitions-mock-is-a-non-visual-polyfill-for-same-document-view-transitions/

It is a spec-compliant JavaScript implementation of Same-Document View Transitions that polyfills the entire JavaScript API surface but that doesn’t do the animation bits.

View Transitions are a powerful Modern Web feature allow for smooth seamless animated transitions two between different states of a web page. They can make for a much more pleasant user experience, but as with any new web platform feature, browser support is not yet fully universal so you need to add some fallback logic to your code.

view-transitions-mock bridges that gap by polyfilling the full JavaScript API surface of Same-Document View Transitions, without the animation bits.

View Transitions are a powerful Modern Web feature allow for smooth seamless animated transitions two between different states of a web page. They can make for a much more pleasant user experience, but as with any new web platform feature, browser support is not yet fully universal so you need to add some fallback logic to your code.

view-transitions-mock bridges that gap by polyfilling the full JavaScript API surface of Same-Document View Transitions, without the animation bits.

Get focused

The post Separate Writing and Formatting appeared first on iA.

Help me out:

I’m looking for examples / use-cases where you want to trigger an action _after_ a programmatic scroll(*) finished.

No need for an actual demo; a description of the use-case itself is good enough.

(*) Things such as `Element.scrollIntoView()` or `window.scrollTo()`.

RE: https://mastodon.social/@btconf/116199043077374654

👀

How to get focused

CSS Anchor Positioning is a powerful tool, but one of the things that you cannot do natively (yet) is animating the position-area property. This blog post introduces a technique to animate position-area changes using View Transitions.

CSS Anchor Positioning is a powerful tool, but one of the things that you cannot do natively (yet) is animating the position-area property. This blog post introduces a technique to animate position-area changes using View Transitions.

On my way back home from #SotB2026 I hacked my way into animating between `position-area` values with View Transitions. The VT automatically gets started by a StyleObserver.

Demo + details can be found on my blog: https://brm.us/animate-position-area

It’s not 100% perfect though, as Firefox doesn’t do anything and Chrome has a 1-frame glitch.

Talk on CSS Anchor Positioning

RE: https://mastodon.world/@webstandards/116147775062588951

You can find the slides of my #SotB2026 talk on my blog: https://www.bram.us/2026/02/28/anchors-aweigh-sotb2026/

Talk on CSS Anchor Positioning