For years, managing UI state on the web meant reaching for JavaScript. But in 2026, CSS has quietly become a state machine of its own. Pseudo-classes track interaction. Media queries read environment and user preferences. :has() observes the DOM tree. Container queries respond to size, style, scroll position, and even anchor placement. Scroll-driven and scroll-triggered animations react to where the user is on the page. And with sibling-index(), CSS can now respond to what's happening next door.

In this atypical "overview" talk, you'll get a practical tour of the CSS features that let you keep and respond to state — from things you can ship today to the cutting-edge stuff landing in browsers right now. Welcome CSS, to the state machine.

Web performance is no longer a luxury—it’s a business imperative: Faster pages boost revenue, improve conversion rates, lift SEO rankings, enhance accessibility and even benefit everyday user productivity.

But the truth is that performance is a continuous discipline, not a one‑off project: Rather than chasing an impossible perfect score, the most valuable gains come from tiny, measurable tweaks that users notice instantly.

In this session we walk through a live, real‑world case study that shows how a handful of practical adjustments can deliver a noticeable speed boost without months of up-front refactoring. You’ll learn:

• Which performance pitfalls surface most often in production code
• How to read and interpret real user metrics that matter
• A toolbox of quick‑win techniques that can be applied today
• When a short‑term fix is appropriate versus when a deeper architectural review is required

By the end, you’ll have a clear roadmap for diagnosing performance bottlenecks, prioritizing the highest‑impact changes and implementing them in a sustainable, incremental fashion—so your own site can start delivering faster, smoother experiences right away.