Day 91 - Style Queries for Collision Detection: When Worlds Collide

🎉 An Awesome CSS Link a Day – Day 91 🎉

Style Queries for Collision Detection: When Worlds Collide

#AnAwesomeCSSLinkADay #YouDontMessWithCSS #CSS

Today we're diving into a new CSS experiment: using style queries to detect when elements visually "collide" on screen. No JavaScript required. Sounds wild? It is.

This trick uses container style queries and keyframe animations to detect layout overlaps, actually introducing collision detection in pure CSS.

📐 Theory: Style Queries Meet Keyframe Physics

Style queries are a part of the CSS Container Queries spec, making possible to apply styles based on computed values of a parent container. In the featured article (showing "a Pong game clone made in pure CSS" 😱, try it in Chrome), style queries are combined with a keyframe animation running on one element (like a bouncing ball).

The other element (like a wall) watches for changes in the animated element's style reacting when the ball "touches" it, triggering a CSS response. This gives the "illusion" of collision response.

• Style queries can react to computed style changes (like size or transform effects).

• By setting flags with custom properties, we can trigger conditional styling in a scoped, declarative way.

• The approach is currently experimental but already functional in modern browsers like Chrome.

🚀 Today’s Link

This CSS-Tricks article is a brilliant walkthrough of this pattern. It includes demo, explanation of how keyframes integrate with style queries, and lots of code visuals:

🔗 Worlds Collide: Keyframe Collision Detection Using Style Queries

You’ll walk away with a totally new perspective on what declarative CSS logic can accomplish.

💫 Giveaways

• Discover how style queries go beyond layout into behavioral CSS.

• Learn how to use custom properties as CSS flags for interaction.

• Explore experimental but functional patterns for game-like behavior in CSS.

• Understand collision detection logic without any JavaScript.

❓ Why This Rocks

• It pushes the boundary of what's possible without scripting.

• Shows the power of style-based reactivity, a lesser-known part of container queries.

• Inspires thinking of CSS as a dynamic language, not just for layout but for logic.

• Provides a bridge between motion design and interaction modeling purely in CSS.

🗣️ Join the Conversation

• Have you experimented with style queries beyond basic responsiveness?

• Do you think CSS should handle interaction patterns like collision detection?

• What’s the most unexpected thing you’ve done with CSS?

• Can you imagine using this in a CSS-only game or simulation?

Let’s talk about this incredible shift, where layout meets logic, and CSS gets smarter.