☄️ Today’s unpopular opinion 😅 What if we could set defaults for HTML attributes via CSS? ARIA, (pre)loading hints, tabindex, popover, inert, etc No new CAS language or text/cas MIME type. Just CSS properties, added as needed. Separate state, no cycles. What stops us? Theoretical purity. [1/4]

This is exactly why we need something like @tabatkins.com's old CAS proposal. Imagine if you could do img, video { loading: lazy; } to change the defaults, and then just use loading="eager" on the actual elements to override.

Side note/rant 😅 You mentioned ponyfills briefly. I'd say they're even more detrimental to standards than it seems. Barely any are ever marked deprecated, so people keep them long term, unnecessarily wrapping the native impl. e.g. object-assign - 100M downloads/week, widely available 2017

“Without polyfills, fallbacks, and progressive enhancement, a single browser has undue power to hold back the Web — whether by choice or by circumstance.” “Developers being able to use web features before wide availability is a win for the Web as a whole.”

"Would you sink millions of dollars of engineering time into something your competitors can render moot, by means of simply …doing nothing?" man, that'd be rough. Imagine what a world we would be in if browser vendors just did that all the time to add stop energy to the process. I wish they didn't.

An excellent post on polyfills, talking through their impact, what issues people (mostly in the standards world) face. Chock full of quotable lines, way too many to include to do the post any justice! Highly recommend reading for a greater understanding of the role of polyfills on the web.

“We don’t stop flying planes because crashes happen. We do a post-mortem and figure out how we can prevent the same accident from happening again. And crucially, the point of a post-mortem is to find the root cause — not to ground the entire fleet.” lea.verou.me/blog/2026/po...

🔥 New blog post: In defense of polyfills A highly influential spec editor expressed the opinion that polyfilling is harmful. I beg to differ. lea.verou.me/blog/2026/po...

This is so exciting. Mark my words: mixins will *completely* transform the way we write CSS more than any other CSS feature has.

If you have kids, I'd strongly recommend @kriskowal.com’s Basic Binary Board Book. You don't see many STEM board books that are so thoughtfully made. Can’t believe it has sold that little, this should be sold out! WTF

Which current, active open source projects would you say have been most influential for today’s front-end development? Eg React, Vue, Svelte, Next, etc

Pfffft, Greek 30 year olds have been doing this since forever 😂😂😂

Proud mom moment: Zoe, aged 7, just said to me and her friend "Color gamut is the colors that can be shown on a screen. Outside of gamut is a color that cannot be shown on a screen." Be still my heart 🥹🥹🥹

When I say that modularity & composability are now crucial as large, coupled codebases consume more context, I see raised eyebrows. Meanwhile, they are constantly running out of tokens while I haven't hit a usage limit in months. If you think architecture no longer matters, joke’s on you.

I proposed this feature in 2023. Safari implemented in 2024. Chrome just shipped it too. This means that it's now a matter of time before it’s available for >88% of web users. Timeline: lea.verou.me/specs/#conti... “But standards are so slow!”

If one user gets it wrong, it *might* be them. If multiple users get it wrong, it's *definitely* you. — Ancient UX proverb

Excellent post by @bram.us. Hits the nail on the head.

(re-)introducing ✨ Emoji Stats for Bluesky ✨ now 100% backfilled!! (and capable of historical analytics down to the hour) technical details and war story below emojistats.at

What do you mean abolishing ICE is not doable? It was created in 2003. There are Missy Elliot songs older than ICE.

Did you know most emojis are perfectly valid CSS <ident>s? Meaning, this totally works in all browsers: --💩: oklch(50% .1 100); background: var(--💩, red); Oooh I’m gonna have a lot of fun with this 🤩 Testcase: codepen.io/leaverou/pen...

Just finished rewatching The Queen’s Gambit. Damn, what an absolute MASTERPIECE. Incredible cinematography, pacing, soundtrack, casting, acting, attention to detail. But my favorite part is how it rejects all modern storytelling tropes we’ve been trained on. 🧵👇

Got a demoralizing "top 100%" from #StateOfCSS? You’re not alone! I got @sachagreif.com to fix the bug, visit stateofcss.com/en-US to see your real percentile. And pssst, did you know you can go back and add pain points you forgot? 😉 Haven’t filled it out yet? Hurry, it closes TOMORROW!! 😱

Was thrilled to see Chrome add vertical tabs, but now I’m struggling to get used to them. Intellectually, I still think they are a UX improvement, but damn, change aversion is real. Those of you who use vertical tabs, did you have a similar experience? How long did it take you to get used to them?

Finally got @svgees.us on here after months of telling him all the good folks have set up camp here! 🦋 His first comment: “Why does @bsky.app throw away the color profile? Look at how washed out my avatar looks 😢” GOOD POINT, WHY?? Hope @bsky.app listens and fixes it. 🌈 Also, welcome!! 👋🏼

Just took #StateOfCSS, DAYS before closing! 😱 Take it now ➡️ stateofcss.com/en-US If you write CSS, this is your highest-ROI 30m this year: results feed directly into browser roadmaps! Partial responses ok. Can pause/resume across multiple devices. My looong wishlist below, for fun+inspiration 👇😅

Zoe, 7 years old, at her first speaking gig at #CSSDay 2026, being interviewed by MC @ohhelloana.blog 😅🥹 Thanks everyone @cssday.nl for being so nice to her. She had a blast! Special thanks to @ohhelloana.blog and @sjoy.lol who are now some of her favorite people. ❤️

See how my Day 2 magenta dress looks brighter than my Day 1 turquoise dress? It wasn’t! RGB gamuts are wider at magentas than turquoises. Gamut mapping is the reason you can still see it was turquoise, even though you can't see the real color 😊 Pic: P3 gamut @ L=73% apps.colorjs.io/gamut/?color...

Oh snort that happened fast.

@lea.verou.me is fighting the good fight here. Issue is a great read!

Fun fact: SVG can do rich tooltips, since its tooltips use an actual <title> element instead of an attribute, but no actual browser seems to support it. Testcase: codepen.io/leaverou/pen... Maybe once browsers add support for ::tooltip they can also fix this? A girl can dream… 🥹

👀 github.com/WebKit/WebKi... Nice to see this (pending) PR by @sakupi01.com that starts the work to add ident() to WebKit. It's a CSS feature I proposed and championed at the CSSWG. See brm.us/ident for details. You can already try it out in Chrome with the CSSIdentFunction CLI flag.

A few of you asked for the pattern for the wine-glass cozy I wore at #CSSday. My crochet-pattern debut — here it is! Have fun with it, and I'd love to see your results if you make one. 🧶 schick.link/pattern @utilitybend.com @lea.verou.me @kevinpowell.co @sjoy.lol @ohhelloana.blog

I would give anything for HTML includes 😭 I help non-tech people build websites at our local IndieWebClub. They don't have any trouble learning a bit of HTML and CSS, but having to set up SSGs just to get common navigation/footers/etc. really stumps them.

The people of #cssday have spoken: we want gamut mapping and we want it NOW!

This is what ChatGPT submit looks like as we speak (for a few days already, on a touchscreen laptop). Probably not what they had in mind.

As @una.im just mentioned in her #cssday talk, the CSS WG recently resolved to insert a ⓘ after EVERY SINGLE INTEREST INVOKER on touchscreens. Here’s a mock of what this would look like for bsky. This is the issue to let the CSS WG know what you think: github.com/w3c/csswg-dr...

#cssday @meyerweb.com you’ll be happy to hear that polygon() will soon take a round arg too! Proposed by yours truly and implemented in Chrome by @yisibl.bsky.social and Jason bsky.app/profile/yisi...

You heard it here first — 2026 is the year you can finally style a select!! It will be in all browsers by the end of the year 🎉🎉🎉 @jakearchibald.com #cssday

It’s not my first time attending (and speaking at) #cssday but holy cow, my mind is blown 🤯 by the quality of EVERY SINGLE TALK. So, so good. I’m so inspired and overflowing with creative energy 🤩

This has been a common theme today at #cssday and it’s true: complaining about broken stuff in browsers is a great way to get them fixed! Don’t silent. Let us know. Have a new idea: write a blog post!

Gamut mapping! #soonbackanswer #cssday @developer.chrome.com @webdevs.firefox.com

Browsers, stop clipping colors! ✊ #cssday

“Researchers found that millions were turning their back on the world wide web, frustrated by its limitations and unwilling to pay high access charges. They say that e-mall, far from replacing other forms of communications, is adding to an overload of information.” Sound familiar?

@codepen.io Is there any way to *disable* blocks in the new editor? Just tried it for a multi-file testcase as it seems to have replaced Projects, but it seems to be running some kind of build process I cannot disable and starts off with three Blocks that I cannot delete. Halp?

🎨😵‍💫 Q: What do you find confusing or difficult about color in modern CSS? Working on my talk for @cssday.nl and if you send me your questions you may find some of them answered in it!

💡Recent insight: gaslighting Claude seems to improve code quality >90% of the time. “You overengineered this, there is a simpler way” “There is a smaller delta that buys us most of the benefits” “There is a more elegant way” “This is not architecturally coherent” …before I even read its code. 😆

Whoa, hey, whoa. `contrast-color()` is baseline now?!? caniuse.com?search=contr...

Thrilled this is out, keeping quiet has been SO HARD! 🤐 I’ve had the opportunity to contribute as a domain expert consultant over the past few months, and saw firsthand the level of thoughtfulness and care that went into it. Proud to have played a small part, and excited to see what folks build! ❤️

The current state of AccentColor/AccentColorText: 4 browsers, 4 different color pairs From left to right: Chrome 148 (stable), Chrome 150 (canary), Safari, Firefox. Details in thread.

🚨 What are some modern web platform (CSS, HTML, JS) features that you wish your AI agent utilized, but doesn't (or gets them wrong)? I’ll go first: - CSS: lh unit, trig functions, nesting - HTML: inert attribute - JS: Regex lookbehind, regex named groups, RegExp.escape(), Object.groupBy()