May Baseline digest: container style queries and the :open pseudo-class
The May edition moves container style queries, the :open pseudo-class for dialog and details, ToggleEvent.source, image-rendering, text-decoration-skip-ink: all, and SharedWorker into newly available. The lh and rlh units, Navigator.userActivation, clip-path, and :user-invalid became widely available. Most of it takes work off JavaScript: state that used to be tracked in a script now has a selector of its own, and a component can finally read a custom property from its parent. Check the exact status for your own audience before you ship, because newly available and widely available are not the same thing.
Source
Majski Baseline digest: upiti o stilu kontejnera i pseudoklasa :openweb.dev Blog · Original published May 1, 2026
The monthly Baseline digest is the shortest way to track what has become safe to use. The May edition brings several things that take work off JavaScript directly.
Newly available
- Container style queries let you style based on a custom property of a parent element, which makes components genuinely self-contained.
- The
:openpseudo-class brings clean CSS for open and closed states on dialog and details. ToggleEvent.sourcetells you which control opened a popover.image-renderingcontrols how an image scales, which matters for pixel art and QR codes.text-decoration-skip-ink: all forces an underline to skip every glyph.SharedWorkeris a background worker reachable from several contexts of the same origin.
Widely available
- The lh and rlh units refer to the line height of the element and of the root element.
Navigator.userActivationchecks whether the user actually initiated something.clip-pathcuts a shape using basic shapes and SVG paths.- The
:user-invalidpseudo-class shows a form error only after the user has done something, rather than on load.
What pays off immediately
:user-invalid is the easiest win on forms, because it solves the familiar problem of red fields shouting before the user has typed anything. The lh unit tidies vertical rhythm without invented numbers.
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