If you needed it, to get a final "yes" from your boss, here it is: the schedule for #btconf Düsseldorf 2026. Now go and grab your ticket ;) beyondtellerrand.com/events/dusse...

Smoke machine powered by CSS! Fully based on web platform tech, such as WebUSB for the DMX connection and CSS for controlling everything. My projects can sometimes get a little bit out of hand. Want to know more? Come see my talk at @beyondtellerrand.com! beyondtellerrand.com/events/dusse...

I am so honoured to be part of #btconf this year. This conference has been such a huge inspiration to me over the years. Been working on this talk for at least a year and expect chaotic energy with lots of weird and wonderful web experiments.

I am very happy to announce another speaker who has been a long-time attendee also. Say hello to @html5test.com, who is going to be part of #btconf Düsseldorf 2026, celebrating 15 years of events for curious minds with us. beyondtellerrand.com/events/dusse...

Smoke machine powered by CSS! Fully based on web platform tech, such as WebUSB for the DMX connection and CSS for controlling everything. My projects can sometimes get a little bit out of hand. Want to know more? Come see my talk at @beyondtellerrand.com! beyondtellerrand.com/events/dusse...

Good morning and happy easter! Today is a bank holiday, but tomorrow I‘ll publish the final schedule for #btconf 2026. What a great line-up. Don‘t be a fool to miss that and get your ticket now. beyondtellerrand.com/events/dusse...

Sometimes I feel like I have too many projects. I move from one to the other and old projects get ignored because I am working on something new and shiny. But that chaos also helps me be creative and challenge me to improve my skills. But today I'm feeling like a mad professor. In a good way.

Putting the final touches on audio input for the DMX/Laser controller project. It analyses the audio and sets a class every time it detects a beat. That allows animations to start, or lights to change colour or the laser to draw patterns. Crazy that all of this is build using web technology.

Great! My clock now randomly thinks it is a VCR. And nobody knows how to set the time on a VCR so it just blinks 12:00. Also it sometimes it forgets to reset after midnight so it goes from 23:59 to 24:00 to 25:00 and on. And yes. I am using a round display for a square digital clock…

Take a Joy-Con and connect it with WebHID, draw a picture in the air and capture it with the sensors. Create an SVG path and insert in the DOM. Apply CSS styling. Sample the DOM and use WebUSB to convert to ILDA and send it to a laser projector. I created the worlds most complicated laserpointer…

Spending my Saturday morning soldering components for my BadClock because even if I look at it sideways, it falls apart. And not intentionally. I am bit scared to plug it in because Raspberry Pi’s are not cheap. And I already have a proper smoke machine.

I’m speaking at 3 conferences this quarter with 3 new talks: 17 April How I blew up my 1980s Oscilliscope with WebAudio at the-web-you-want.org 27 - 28 April The Web Beyond the Edges of the Browser Window at beyondtellerrand.com 11 - 12 June CSS Doom Lasers at cssday.nl Get your tickets now!

Beyond Tellerrand @beyondtellerrand.com is happening again on April 27 and 28th in Dusseldorf. And a little birdie told me a certain someone is going to show off their BadClock™ and much more. Lasers. Yes. Lasers and smoke and more... Tickets: 🎟️ beyondtellerrand.com/events/dusse...

Good issue this week, with plenty to dive into. Includes links from @csswizardry.com, @html5test.com, @meodai.bsky.social, @rachelandrew.bsky.social, @jakearchibald.com and others! ⭐️ frontendfoc.us/issues/735

I'm so in love with this new menu for my BadClock™. I feel like I am doing character animation instead of coding. The clock is starting to get a personality.

Doom CSS has a far smaller CSS and JavaScript footprint than every single client website's homepage I work on. A good reminder of how unnecessarily weighty modern websites are.

This is my paper clock. It prints a line with the current time every minute. Or sometimes it draws an analog clock. And if it doesn’t feel like it, it just draws a random doodle. It also has an unhinged mode where every minute is… well never helpful.

I got a question about my BadClock™: don't the gears destroy themselves when you move the hands independently. Of course not. It is a digital clock. It doesn't have gears. Don't be silly. There is a risk of winding it up too much though. It locks up the whole gear mechanism and all that energy...

What's the best way to showcase modern CSS features? By making games! This time it's the Dino Game 🦖 by @developer.chrome.com css-tip.com/dino-game/ 100% CSS magic playable with the keyboard. Yes, you can jump and crouch with the arrow keys! 👀 Don't search for the JS, there is none.

Niels Leenheer has ported Doom to an unexpected platform: Cascading Style Sheets, normally used to control the layout and appearance of modern web pages.

Does your clock really need a full Box2D physics model. No. But is does make it a lot more fun. This is my BadClock™. It runs late when you don’t wind it. Hands fall off when you’re too rough and it forgets how DST works. So it may adjust your clock in the wrong direction. Or not. Who knows.

Hey! Looks like I’m on Hackernews and the comments are… actually pretty on point and positive. Wow! 🤩 news.ycombinator.com/item?id=4755...

Amazing!!! Maybe now people will stop asking me to do it. 🤣 Great work by Niels!!! 👏

I still can’t believe this is all CSS and a couple of divs in the browser. And that it runs so smooth on my phone. I just love the top view - including that transition. And the way those fireballs just come hurdling towards you.

CSS is DOOMed! I've build DOOM in CSS and every wall, floor, barrel, and imp is a div, positioned in 3D space using CSS transforms. cssdoom.wtf Try it out! But... not every browser can handle it. This is taking the browser to its limit. Chrome has some issues. Safari too. Bugs will be filed.

Another first in this project. I've written MathML for my blog post to explain some of the math that is involved with projecting walls in 3D space.

Oh no! Another rabbit hole.

Pretty much done now. Added some NES.css inspired bitmap style help text and buttons. The buttons are styled by using a 5 step box-shadow. 4 for adding the border around the button and one inset for the highlight.

For an upcoming talk I needed to visualize how you can use WebAudio to draw shapes on an oscilloscope. So earlier this week I created this animation. How did I do it... it's build in JS, drawn on a canvas. Then using WebCodecs API encoded to H.264 and exported as an MP4 file. The web is awesome.

I think I found another limitation of the CSS rendering engine. DOOM uses the walls around the area outside as a signal of where the sky should be drawn (pink). These are walls that block whatever is behind it. That is cheating because in "reality" you see can the map from that viewpoint.

Some people have told me they wish they could go to CSS Day or Smashing Conf where I'll be talking this year, but the price is prohibitive, which I totally get. But the CMD school of design is hosting a completely free conf around both of them, with great lineups. the-web-you-want.org

Excited to both finally get to meet and have an unplugged session with @matuzo.at at the upcoming @smashingconf.com Amsterdam! The full schedule: smashingconf.com/amsterdam-20... If you don't have a ticket, it's not too late, and this link gives you a bit of a discount: ti.to/smashingmaga...

Been sick for the last two days - so no updates to ccsDOOM yet. Just a few rendering issues left, a crashing Safari on iOS to investigate and got to finish my blogpost. So soon. Did manage to add touch controls, fullscreen and gamepad support.

5 weeks to go before we celebrate 15 years of #btconf in Düsseldorf. If you need positive energy and want to be creatively loaded, don’t miss out. beyondtellerrand.com/events/dusse...

Event tip: 🎯 CSS Day (June 11–12, Amsterdam) Two days fully dedicated to CSS: layout systems, modern selectors, performance, animation, a11y, security & upcoming specs straight from the people shaping them. If CSS is your craft — this is your event! 👥 Fronteers members get €100 off 👉 cssday.nl

What is is this? Oh.. This is just me playing responsive DOOM.css on my phone. Is it playable? Kind of. Does it stutter? Absolutely. Did I just play for hours? Yeah! Detail: The weapon and controls are using anchored positioning to the top of the status bar, because we don’t know how it will wrap.

Too bad you can't register first level .om domains. I really liked cssdo.om. But even if I could, I don't have that kind of money lying around just for fun. I just spend it all on a laser projector and flame thrower.

Does anybody know the status of CSS if() in Safari and Firefox? For DOOM.css I want move the culling from JS to CSS - hiding div's that are not visible from the viewpoint of the player - and if() is a hard requirement. Yes, this is CSS. Nothing theoretical about his. It works in Chrome!

DOOM.css is getting somewhere. Gameplay is pretty much done completely in JavaScript, but the whole rendering is 100% CSS. This map is 768 div's with 3D transforms. Added a nice spectator view as well which is literally just adding a couple of CSS custom properties override for the rendering.

I don’t have time to do as many conference talks these days but @cssday.nl always has a special place in my heart. It’s such a fantastic conference, both for the content and the community. If you can go, don’t miss it!

Trying to recreate the Spectre shimmer effect with SVG filters for DOOM.css. Not perfect, but I think close enough. Really feel like I pushing against the boundaries of the browsers compositor here. Especially on larger levels the fans on my MacBook Pro are blowing full force.

Today is my last day with the Deno team 🦕💖💔 I know they're gonna keep making awesome things. But now *I* need to make awesome things for someone else! If you're looking for a DevRel with a JS focus and extra sparkle, get in touch!

Back to proper math. Implementing keystone and barrel correction for the laser projector. Yes. That is level E1L1 of Doom. Yes you can run Doom on a laser projector. Kind of.

CSS Doom Lasers at #cssday? Yes. Buy a ticket and join us! cssday.nl/tickets.html But tonight we rule the world... eh... well, we play Offline Laser Dinosaurs 🦖 all controlled from the browser using WebUSB and an USB to ILDA converter. The web is so awesome.

CSS Doom Lasers at #cssday? Yes. Buy a ticket and join us! cssday.nl/tickets.html But tonight we rule the world... eh... well, we play Offline Laser Dinosaurs 🦖 all controlled from the browser using WebUSB and an USB to ILDA converter. The web is so awesome.

So happy to be back on the CSS Day stage this June with so many other fantastic speakers. And I can't wait to show what I've been working on the last year or two. Yes it will be about Doom, Lasers and CSS, and so much more. ✨ I do feel I've hit peak talk title with "CSS Doom Laser".

Also, we announce new speakers today. @kevinpowell.co Lea Verou, @matuzo.at and @html5test.com will join us on 11th and 12th of June. No flamethrowers will be used. Probably. cssday.nl

I for one think these are important topics to address. One can never know too much about lasers and flamethrowers.

Writing a CSS Day newsletter about flamethrowers and doom lasers. We must address the legitimate concerns of our audience.