Josh Tumath

Hello to recent new followers! I guess I should give a brief introduction. I'm Josh and I've been working on the BBC's Design System team for over five years. My passion is CSS and I recently had the privilege of joining the CSSWG in the summer. I hope to serve you all well. 🫡

Please watch this.

The first Public Working Draft of Animation Triggers has just been published, introducing mechanisms that affect animation playback based on DOM events from user interaction or on entering or exiting ranges on animation timelines. www.w3.org/TR/2026/WD-a... developer.mozilla.org/en-US/docs/W...

After the CSSWG resolved to explore mesh gradients, the chair also made me an editor of the CSS Images 5 spec. 😱 FYI, I have absolutely no idea what I'm doing, but thankfully I have help from some very clever people. Sadly I will have to spec what happens if someone makes a mesh gradient like this:

Yesterday, the CSSWG accepted my proposal for mesh gradients and diffusion curve gradients! Want to make gradients like this natively in CSS? Well, we've started the work on it. It's coming! Here's the Explainer: github.com/w3c/csswg-dr...

Finally looked into CSS scroll triggered animations and wrote down what I learned! Special thanks to Bramus for answering some of my questions cydstumpel.nl/css-scroll-t...

These were all brilliant speakers! Thank you again to @alexolder.com and @lurkmoophy.bsky.social for another wonderful, organic, homemade, wholesome conference.

The @webdevconf.com somehow finished early so we had an extra bonus talk from @lurkmoophy.bsky.social The intro alone took about 10 mins as Luke told us the various things that they have tried to do. 😂 But that was sort of the point. They talked about the effect of doing too many things at once.

We had Duncan Petrie talking about some incredible and creative ways of using requestAnimationFrame which involved Fabergé eggs and a springy chicken crossing the road and very well animated spiders! @webdevconf.com

Hooray! I'm here at Bristol for @webdevconf.com! Looks like I'm speaking first tomorrow. Very excited! If you're here, come say hi!! I'd love to meet you.

I like that @keithamus.social keeps trying to carry old things across the finish line. It's such a shame that so many thing fizzle after so much work and good ideas. The web needs more (paid) people doing this.

“Let me make it clear: without people at the top of their game sharing their experience and knowledge—regardless of whatever ‘game changing’ technology is in place—we are pulling up the ladders and committing our industry to stagnation and death.” bell.bz/youll-miss-p...

If you work on websites for ordinary web browsers, you are truly blessed. Working at the BBC, I am always shocked by how bad the built-in web browsers are on smart TVs. They fork browsers and rip out lots of web platform features. Apparently one made Math.random() return the same number! 😂

I'll be speaking at Web Dev Conf next month, talking about the work we've been doing at the CSS Working Group to make your website more accessible for users who want larger text! Come along! It's a lovely conference with lovely people in a lovely city - and it's not expensive!!

The plot thickens.

We've made it to September which means WDC2026 is just over a month away! Tickets are just £99! With awesome speakers: @joshtumath.uk @amyhupe.bsky.social @paavandesign.com @cjforms.bsky.social @duncanpetrie.com @hidde.blog In the great city of Bristol! webdevconf.com

Call me naïve, but I think the Web should be making it *easier* to create accessible UIs than inaccessible ones. Instead, once you go beyond the basic primitives, the platform is a minefield: the obvious thing to do is rarely accessible, and devs must jump through hoops to make it so.

So @nerdy.dev and @matuzo.at have got me addicted to Angine de Poitrine. I am officially a fan. open.spotify.com/track/19MAOZ...

Does anyone ever feel limited by the visible light spectrum? All we can use in our designs is various shades of red, orange, yellow, green, cyan, blue, purple, magenta and grey. We could really do with another one for our design system.

OK, I'm persuaded. For a toggle in the header or footer, a toggle between 'system colour scheme' ↔️ 'the opposite' is better than system ↔️ light ↔️ dark. Lea is a master of user experience.

Come along! This is a fantastic conference!

I've just been in my first mosh pit. It was for the Oxford symphony orchestra. 😂

I'm at my first music festival. Are you proud of me, @letorey.co.uk ?

Count Binface takes down Newsnight. 😂 (And raises good points about the need for more funding for investigative journalism. @backthebbc.bsky.social )

Last month, I was speaking at @cssday.nl on the new <meta name=text-scale> tag. I've just published a blog post with my slides and summary. www.joshtumath.uk/posts/2026-0...

I'm so grateful to Bramus for making this. It's awesome. Wouldn't you love to make these kinds of gradients natively in CSS - with the browser's graphics engine giving you a native hardware-accelerated render?

And the #cssday aftermovie is also online. www.youtube.com/watch?v=IarC... The full videos will follow on Conffab, but it'll take a little while longer.

Reminder: The State of CSS Survey is closing *SOON*, so **NOW** is the moment to complete it. stateofcss.com/en-US/ This survey directly influences efforts like Interop and feature planning, so this is **YOUR** moment to let browser vendors know what you find missing on the web!

It's about time I listed all of the talks that I've done on my website. So here they are. There are more which I can't remember, but these are the ones I remember. Let this be a lesson to you all. Make note of the things that you've done. Because I don't. 😅 www.joshtumath.uk/talks/

Hahaha so interesting. It's like the web platform equivalent of when the newspaper was invented and people grumbled about people reading their newspapers on trains (like we do today with our phones).

The #CSSDay community had incredibly helpful feedback about <meta name=text-scale>. Lots of different ideas for how to stop headings from scaling at the same rate as body text. Good feedback on how the large text on mobile will be a problem for languages with very long words, like German.

I am wildly excited for what the next-gen does with #CSS

This might be my last year living in the UK. Next spring, I'm hoping to move to Japan and I plan to start looking for jobs soon. I would love to have a job that would let me continue or increase my participation in the CSSWG. If anyone knows an org in Japan that could hire me, please let me know

We didn’t talk enough about how @sjoy.lol just casually, and magnificently, gave two talks in 24 hours. #CSSDay With a quick shout-out to @localghost.dev ✨

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...

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