CSS Day

.css-day.2025 {
  date: '5th and 6th of June';
  speakers: '14 in one track';
  location: 'Amsterdam - NL';
}

See our schedule

Our speakers

Our line-up is now complete.

Day 1

Stephen Hay: MC

Stephen Hay is a creative director, designer, author, and speaker with a passion for code, design processes, and systems thinking. With a background in graphic design and fine art, he became an early advocate for responsive design, design systems, and using CSS as a design tool. He's the author of Responsive Design Workflow, co-author of Smashing Book #3, writer of countless articles on design topics, and has spoken at industry conferences worldwide. Stephen is always exploring smarter ways to work and create.

Level up your scroll UX

Slide by slide, CSS feature by feature, we'll incrementally enhance and craft a rad scroll experience. Normally a pain in the box; styling and managing scroll across touch, keyboard, mouse and more PLUS juggling each operating system's slightly different affordances, can be daunting. We’ll emerge victorious, nay, elegant! Learn terms like scroll hint, overscroll behavior, overscroll effect. Plus, when to use what, and a whole bunch of niche details about CSS and scrolling. It’s definitely something people do on your site right? Have you polished it or is yours a bit basic? Upgrade time.

Adam Argyle

Adam is a bright, passionate, punk engineer with an adoration for the web who prefers using his skills for best in class UI/UX and empowering those around him. He’s worked at small and large companies, and built an app for pretty much every screen (or voice). He is capable of over-engineering, but spends lots of brain power not to. Loves CSS, loves JS, loves great UX.

A Dao of CSS

What if we stopped trying to control the web—and started working with it?

In this talk, I return to A Dao of Web Design, an essay I wrote 25 years ago, to look again—this time through the lens of CSS. Drawing on a close reading of the Tao Te Ching, I explore how CSS isn’t broken or lacking—it’s just deeply misunderstood.

CSS is not a language of force. It doesn’t tell the browser what to do. It suggests, it yields, it adapts. It’s declarative, contextual, and quietly powerful—more in tune with Taoist ideas of the dao–flow, humility, and non-action (wei wu wei) than we may realise.

By understanding CSS through this lens, we see the cascade, inheritance, and layout not as problems to overcome, but as patterns to follow. We stop chasing pixel perfection and start designing systems that respond—gracefully, appropriately, and even beautifully—to the world around them.

This isn’t a talk about new techniques. It’s about letting go. And perhaps seeing CSS—and the web—with new eyes.

John Allsopp

John Allsopp has been working on the Web for nearly 30 years. He's been responsible for innovative developer tools such as Style Master and X-Ray, and his ideas formed the foundation for Typekit, now Adobe Fonts, and the entire concept of Responsive Web Design.

His writing includes several books, including Developing With Web Standards and countless articles and tutorials in print and online publications. He also organises Web Directions.

His "A Dao of Web Design", published in 2000, is cited by Ethan Marcotte as a key influence in the development of his acclaimed 2010 Responsive Web Design, which begins by quoting John in detail, and by Jeremy Keith as "a manifesto for anyone working on the Web".

Is Sass Dead Yet? CSS Mixins & Functions &c.

Sass has inspired new developments in CSS for over a decade – from variables to nesting, and now author-defined CSS mixins and functions. As these features make the jump from Sass to CSS, they tend to change in significant ways. So what can we do with CSS functions and mixins, how will they be different from the Sass tools that inspired them, how can you help in the spec process, and what other features might this open up in the future? Is this finally a death blow for CSS pre-processors? (No, but let’s talk about it anyway!)

Miriam Suzanne

Miriam is an author, artist, developer, and open web advocate. She’s a co-founder of OddBird, Invited Expert with the W3C CSS Working Group, and member of the Sass core team. Offline, Miriam spends her time repairing clocks, knitting socks, or creating hybrid performances with Teacup Gorilla & Grapefruit Lab.

CSS tried to come for my job — A practical guide to View Transitions for creative developers

CSS has gotten more powerful in terms of layout for the last couple of years, but lately, it’s also been creeping into places that have traditionally relied heavily on Javascript.

Features like scroll-driven animations and view transitions are changing what’s possible natively in the browser. As a creative developer, I’ve spent years building animated sites using GSAP, Swup, and Javascript-heavy custom setups.

In this talk, I’ll share what I learned switching from full-control Javascript animations to CSS-driven transitions. I’ll talk about what works, what doesn’t (yet), and how these tools are reshaping the creative developer’s workflow. If you’ve ever spent days tweaking timelines or writing math for transitions, this might just convince you to let CSS take over (at least a little).

Cyd Stumpel

Cyd is a freelance creative developer and part time teacher at the Amsterdam University of Applied Sciences. She creates accessible, award winning websites for everyone; from large organisations like WeTransfer and Amnesty International to creative agencies and freelancers. She’s got an eye for details and loves to turn flat designs into rich experiences.

Cyd has mostly focused on JavaScript animation over the last couple of years but has rediscovered her passion for CSS this year, rebuilding her portfolio with View Transitions and Scroll Driven Animation.

Select it! Styling new HTML UI capabilities

We are getting spoiled with increased UI capabilities, partially thanks to the efforts from the W3C community group Open UI. One of those features is the customizable select. This new capability for selects seems to love new CSS features, and that love is mutual.

This presentation is a love letter to W3C community groups, new UI capabilities, and CSS, showing you how to combine features such as anchoring, transitioning, scroll snapping, and much more to create fun, progressively enhanced, customized select elements.

Brecht De Ruyte

Brecht De Ruyte is a self-taught front-end developer located in Belgium with a passion for UX and Design. During the day you can find him working at iO, a full service agency. Besides that, he is also a Google Developer Expert, Smashing Magazine writer and blog owner of utilitybend.com. He also participates in the W3C communities: Open UI and CSS-next.

Rachel Andrew: Multicol and fragmentation

Rachel works for Google as content lead for Chrome Developer Relations, publishing to web.dev and developer.chrome.com. She is a front and back-end web developer, speaker, and author or co-author of 22 books including The New CSS Layout. Rachel is a Member of the CSS Working Group, and can be found posting photos of her cats on Mastodon and being all business on LinkedIn.

Brad & Ian Frost

In addition to speaking at the conference Brad and Ian will give an Advanced Design Tokens workshop on Wednesday 4th of June, the day before the conference.

Brad

Brad Frost is a design system consultant, web designer & developer, speaker, writer, teacher, musician, and artist located in beautiful Pittsburgh, PA. He helps people establish & evolve design systems, establish more collaborative workflows, and design & build software together. He is the author of the book Atomic Design, which introduces a methodology to create and maintain effective design systems. He co-hosted the Style Guides Podcast and has helped create several tools and resources for web designers, including Pattern Lab, Styleguides.io, This Is Responsive, Death to Bullshit, and more.

Ian

Ian Frost is a front-end architect, technical lead, and consultant passionate about helping developers level up their skills.

Over the last decade, Ian has developed many design systems in a variety of technologies, including Web Components, React, Angular, and Vue. Ian has partnered with tech leads, developers, and designers from numerous Fortune 500 organizations to successfully establish, implement, and maintain robust design systems and token architectures. He views this work as a blend of art and science and is eager to share hard-earned lessons to make the process easier for others.

Before becoming a web designer, Ian worked as a professional meteorologist. Outside of coding and forecasting, he enjoys playing music, participating in sports, and spending time with his wife and son.

Day 2

Bramus: MC

Bramus is a web developer from Belgium. He’s part of the Chrome Developer Relations team at Google, focusing on CSS, Web UI, and DevTools. From the moment he discovered view-source at the age of 14 (way back in 1997), he fell in love with the web and has been tinkering with it ever since.

Before joining Google, Bramus worked as a freelance developer in various frontend and backend roles. For seven years he also was a College Lecturer Web & Mobile, educating undergrad students all about HTML, CSS, and JavaScript — in that order.

Scope in CSS

I hate to be the one to tell you but writing CSS is half thinking about scope. You don’t always need them, but there are plenty of tools out there that help with scoping one way or another. They are worth considering as they help with a variety of problems a team can run into while building and maintaining a website. CSS itself is getting in on the action with @scope, a relatively new at-rule. It’s got some interesting tricks up it’s sleeve, but doesn’t do the same sort of things that build tools can do related to scope. So I guess we’d better talk about it all together.

Chris Coyier

I’m a web designer and developer that tries to help other people get better at those things.

I’m the co-founder of CodePen, a social development environment for web designers and developers. CodePen is a front-end focused IDE in the browser allowing people to write HTML, CSS, JavaScript, and related languages. It’s as much of a community and social network as a coding platform.

Along with Dave Rupert, I’m the co-host of a podcast called ShopTalk, a show about (you guessed it) building websites. We’re over 10 years and 500 episodes strong!

I built CSS-Tricks, a website all about building websites, and ran it for 15 years, from 2007 to 2022, before selling it to DigitalOcean.

I’m big on the power of writing as a way to improve yourself and be successful.

Smart layouts

Today is the best time to start learning how to use modern CSS features to build truly responsive components. Responsive design doesn’t mean designing for the viewport anymore. There are many factors that can affect a component’s layout.

For example, even though container queries and CSS :has() are well supported, there is still a gap in using them to their full potential. CSS now is like a football team with solid players but no coach to bring out their best. In this talk, I’ll walk you through my process of building smarter layouts that are aware of their surroundings and context, in the hope of inspiring you to take the next step and use modern CSS in your workflow.

Ahmad Shadeed

Ahmad Shadeed is a UX designer and front-end developer from Tulkarm, Palestine, who enjoys tackling interesting design and development challenges. He has written extensively about CSS, accessibility, and RTL (right-to-left) styling and is the author of a book on debugging CSS, helping developers improve their CSS debugging skills and reduce the time spent on fixing CSS issues.

Ahmad also coined the term Defensive CSS, a concept focused on writing future-proof styles. Through his work, he aims to bridge the gap between design and development, making it easier for designers and developers through practical articles and guides.

When he’s not at his computer, he enjoys dialing in a new espresso blend, trying to perfect a latte art design beyond the tulip, baking cookies, going out to nature and take photographs of his child.

Form control styling

Text inputs, checkboxes, radio buttons, sliders… Form controls have been part of the web since the beginning, but styling them can still feel like a battle.

If you’ve spent time struggling to figure out countless lines of CSS to make them look right, or rebuilt native elements from scratch because they weren’t customizable enough, you’re not alone.

In this session, we’ll explore why HTML form controls have been so hard to style — and introduce upcoming improvements that will make them easier to customize, using only the power of CSS.

You’ll also get a peek at how form controls have evolved, and how the new enhancements fit into the broader web ecosystem. If you’ve ever struggled with form controls, this talk will give you practical insight and a glimpse of what’s next.

Tim Nguyen

Tim is a WebKit engineer at Apple. His interest in web technology developed through years of web design and many contributions to Firefox’s user interface. Those contributions led him eventually to hack on browser engines, starting with adding support for conic gradients to Gecko. These days, he is a prolific WebKit contributor. Features he’s implemented include the <dialog> element, popover, and View Transitions.

He grew up in Paris and lives in San Francisco.

Building a Computer with CSS

Ever wondered how a computer actually works? What a CPU is actually built of? And if it's possible to build one using only CSS? If so, this talk is for you.

We’ll break down the fundamentals of a CPU and rebuild them entirely in pure CSS. Using clever selectors and advanced styling tricks, we’ll construct working logic gates and even assemble them into a functional calculator. No JavaScript, no magic, just CSS pushing the boundaries of what’s possible.

Amit Sheen

Amit is an experienced web developer, specializing in CSS, design systems, animations, and creative coding. He has a pathological curiosity and a constant desire to learn new things, and loves sharing his experience and explorations with the community.

Refactoring CSS

In recent years, updates in CSS have given us many exciting possibilities for creating modern, dynamic web experiences. Yet, for many developers, the day-to-day reality often involves working within the constraints of legacy codebases.

In her talk, Ana will explore practical strategies for navigating the challenges of maintaining and modernising legacy CSS. Is refactoring an option? What are the pros and cons of this? How do we approach stakeholders? How do we prioritise and initiate changes, measure improvements and quick wins?

With her many years of finding the balance here, Ana will share lessons from past experiences and look forward to what's ahead.

Ana Rodrigues

Ana works as a front-end developer at tech-for-good agency Hactar. She started coding as a teenager building fan sites, and has been working as a front-end developer for the last 12 years.

Nowadays, Ana spends most of her free time experimenting on her personal blog and is particularly interested in ethics, IndieWeb, sustainability, privacy, and all things CSS.

display: green; applying the web sustainability guidelines

The tech sector has an elephant in the room: we use too much energy. In 2024, the World Bank estimated the internet to account for 1-4% of global greenhouse emissions, similar to aviation. The good news is: there are documented and measurable opportunities to improve. From code to infrastructure. In this talk, we’ll look at best practices from the W3C’s new Web Sustainability Guidelines and beyond, focusing on lessons you can apply today.

Hidde de Vries

Hidde is a freelance front-end, design systems and accessibility specialist (CPWA). He is also involved in the W3C’s Open UI Community Group and Accessibility Guidelines Working Group. His favourite programming language is CSS and he strongly believes in a web that puts people first. Hidde writes about these things and more on hidde.blog. In his free time, he works on a coffee table book covering the video conferencing applications of our decade.

The goose and the common

The web is at an inflection point. Big Tech owns the major platforms, the major browsers, the biggest websites, and carves the Web up between themselves. Users are under constant surveillance in Big Tech’s walled gardens, which it then pollutes with its AI weed killer. What can we do to ensure that the web remains for everyone, as Sir Uncle Timbo intended?

Bruce Lawson

A veteran of the browser wars, many a standards skirmish and an accessibility apocalypse or two, Bruce now leverages synergies for Vivaldi browser.

When web standards finally makes him a billionaire, Bruce has no plans to go to Mars, but will continue making music with the cruellest months.