When Silly Design Ideas Turn Into Something Beautiful
Every once in a while, a design concept lands on your desk that makes you raise an eyebrow. Columns of content sliding in opposite directions as the user scrolls sounds like the kind of thing a designer pitches on a Friday afternoon. But once you see it in action, it clicks — and suddenly you need to build it. That's exactly the kind of challenge that scroll-driven animations were made for, and it turns out the implementation is far more approachable than you might expect.
In this article, we'll walk through how to create a layout where multiple columns of items move in opposing directions in response to the user's scroll position — all using modern CSS, with no JavaScript required. If you've been curious about scroll-driven animations but haven't found the right project to dive in with, this one is both fun and genuinely practical.
What Are Scroll-Driven Animations?
Scroll-driven animations are a relatively modern CSS feature that allow you to tie an animation's progress directly to the scroll position of the page or a scrollable container. Rather than triggering an animation at a specific scroll point (the classic "scroll-triggered" approach), scroll-driven animations let the user literally scrub through the animation by scrolling up and down.
This is different from the scroll-triggered approach that relied on JavaScript-based observers or libraries like GSAP's ScrollTrigger. With scroll-driven animations, the browser handles everything natively — meaning better performance, less code, and smoother results. The feature is currently well-supported in Chrome and Safari, which covers a healthy portion of modern web traffic.
It's worth noting that if you're building for accessibility-conscious users, scroll-driven animations should always respect the user's reduced motion preferences. The prefers-reduced-motion media query is your friend here, and any well-built implementation should check for it before applying motion effects.
The Core Concept: Opposing Column Movement
The visual idea is straightforward: you have two or more vertical columns of items. As the user scrolls down the page, one column moves upward while the adjacent column moves downward. This creates a dynamic parallax-like effect that feels fluid and intentional rather than gimmicky — especially when applied to image grids, portfolio showcases, or product listings.
The trick is that both columns are animated using the same scroll timeline, but one column's animation is inverted. This means you only need to define the motion once and simply reverse the direction for alternating columns.
Setting Up the HTML Structure
The markup is intentionally clean and minimal. You'll have a parent wrapper element that holds two or more column elements, and each column contains a series of individual items. A structure like this works well:
- A container div with a class like
.opposing-columnsacts as the parent and scroll context. - Each direct child div (e.g.,
.opposing-column) represents one of the moving columns. - Inside each column, individual items (e.g.,
.opposing-item) hold your content — images, cards, text blocks, or whatever fits your design.
Keeping the HTML semantic and flat makes it much easier to target elements with CSS and apply animations without complex selectors or JavaScript traversal. The simplicity of the markup is actually one of the most appealing parts of this approach.
Applying Scroll-Driven Animations With CSS
Once your HTML is in place, the CSS does the heavy lifting. The key properties you'll be working with are animation-timeline and animation-range, which are the core of the scroll-driven animation API in CSS.
You'll define a @keyframes rule that translates the column along the Y axis — moving it upward or downward by a set amount. For the first column, the animation moves elements in one direction. For alternating columns, you apply the same animation but either negate the translate value or use a separate reversed keyframe.
The animation-timeline: scroll() value is what binds the animation to the scroll position. By default this links to the nearest scrollable ancestor, which in most cases is the page itself. You can also scope it to a specific element using named scroll timelines, giving you fine-grained control over which scroll container drives the animation.
The animation-range property lets you control when the animation starts and ends within the total scroll range. Setting it to cover the full scroll range (from 0% to 100%) means the columns animate throughout the entire scrolling experience, which gives the most immersive effect.
Handling Reduced Motion and Accessibility
Accessibility should never be an afterthought with motion-heavy effects. Wrapping your scroll animation CSS inside a @media (prefers-reduced-motion: no-preference) block ensures that the animations only apply for users who haven't opted out of motion on their operating system or browser. Users who experience motion sickness or who have vestibular disorders will thank you for this consideration.
When motion is disabled, the columns simply render in their default stacked layout — fully readable and functional, just without the movement. This is a graceful and responsible degradation that should be standard practice for any animation work on the web.
Browser Support and Progressive Enhancement
As of this writing, scroll-driven animations have solid support in Chrome and Safari. Firefox support has been developing, so it's worth checking current compatibility tables before deploying to production. The good news is that CSS scroll-driven animations degrade gracefully — if the browser doesn't understand the property, it simply ignores it, and the layout still works perfectly as a static design.
This makes scroll-driven animations an excellent candidate for progressive enhancement. You build the baseline experience first, then layer in the scroll-based motion for browsers that support it. No polyfills, no JavaScript fallbacks, no extra complexity.
Why This Approach Is Worth Exploring
Beyond the visual appeal, this technique demonstrates just how capable modern CSS has become. What once required a JavaScript library, scroll event listeners, and carefully managed performance optimizations can now be achieved in a handful of CSS declarations. The browser handles the animation timing, the compositing, and the performance — often by offloading the work to the GPU.
For developers looking to push the boundaries of what CSS can do, scroll-driven animations are one of the most exciting additions to the language in recent years. The opposing columns effect is a great first project to get your hands dirty with the API, but the same principles extend to parallax backgrounds, progress indicators, sticky navigation transitions, and far more.
So the next time a designer pitches you something that sounds a little out there, consider that modern CSS might just be ready for it. Scroll-driven animations have opened a new chapter in what's possible without touching JavaScript, and the opposing columns technique is one of the most satisfying examples of that potential in action.