Another #CSSonly `::scroll-*` demo! This one keeps things a little simpler, using scroll markers as tabs and scroll-triggered animations to bring the selected tab’s content to life. ⚠️ Currently only works in Chromium-based browsers. See the full demo on @codepen.io codepen.io/editor/cbols...
Chris Bolson
Chris Bolson
@cbolson.bsky.social
The best dependency is no dependency 🔗 https://codepen.io/cbolson
98 followers66 following148 posts
I don't normaly share this sort of thing but this one hits close to home. Billy is my nephew. 7 years ago mine and my families life got flipped upside down and changed forever On the morning of 14th July 2019 my sons 5th birthday of all days I suffe... fundraise.cancerresearchuk.org/team/billys-...
Another `:scroll-*` demo — an interactive CSS solar system! 🪐 Advanced `attr()` pulls planet data to define orbits and speeds, while `::scroll-marker` brings the planets to life. Always fun to see what CSS can do! See the full demo on @codepen.io codepen.io/editor/cbols... #CSSOnly
🎃 A little Halloween FizzBuzz fun! 100 floating numbers, some CSS random(), a bit of sibling-index(), and some spooky surprises hiding behind the numbers. 👻 Hover over one to see what happens… See the full demo on @codepen.io codepen.io/editor/cbols... #codepenchallenge #FizzBuzz #Halloween
It is always a great privilege to have one of my demos included in Álvaros monthly round up. Thanks!
10 Cool CodePen Demos - September 2026 alvaromontoro.com/10-cool-code... In this edition: CSS art, groovy animations, textures and text, menus, charts and pie charts (and doughnuts), LEDs... and more! #webdev #javascript #css #html #codepen
A CSS-only circular nav using experimental `::scroll-*`, `animation-timeline: scroll()` and anchor positioning. Scroll drives the items around the circle, with anchors handling the current label and prev/next controls. ⚠️ Chromium only. See the demo on @codepen.io: codepen.io/editor/cbols...
Chris Bolson reposted
To practice and learn, I checked the accessibility of La Liga teams' homepages ⚽ I documented the results, the issues I found, the methodology I followed (combining automated+manual tests)... and shared it on my blog: alvaromontoro.com/blog/68112/l... #LaLiga #Accessibility #A11y #WebDev #Soccer
Chris Bolson reposted
📝 When and how CSS custom properties are calculated might not be what you expect, and it has a big impact on your styles. Here's how it works: jakearchibald.com/2026/css-cus...
Chris Bolson reposted
I'm sure you already heard about the big update to @codepen.io. If you're still trying to work your way around it @chriscoyier.net sat down with me to walk me through all of the changes. youtu.be/q_0RweY2VJc
From 13 teams in 1930 to 48 teams in 2026 ⚽ This World Cup timeline demo covers every tournament, revealing stats, results and highlights using CSS animation-trigger with a scroll-driven animation fallback. See the demo on @codepen.io : codepen.io/editor/cbols...
A new #cssonly demo: scroll-triggered counters. In supporting browsers (Chrome only currently), counters count up when scrolled into view. Built with `timeline-trigger`, `animation-trigger`, `attr()`, `@property` and `sibling-index()`. See the demo on @codepen.io: codepen.io/editor/cbols...
As the 2026 World Cup enters the knockout stage, I challenged myself to build a CSS-only tournament bracket ⚽️ Using attr(), style queries and plenty of :has(), the bracket updates as you pick each winner—all without JavaScript. Check out the demo on @codepen.io : codepen.io/editor/cbols...
Well worth the read! My mind is already taking these gap decorations where they were not built to go 😆
📝 New CSS Article! I did a quick exploration of the new "Gap Decorations" thing, and I ended up doing a lot of fancy stuff except for decorating the gaps 😅 master.dev/blog/lets-pl... Read my latest article to learn a lot of nice tricks around this feature.
Chris Bolson reposted
A bit late (in my defense, I've been all over the place in June), but here's the 10 cool CodePen demos from May... alvaromontoro.com/10-cool-code... generative art, CSS art, clocks, shape tools, components, animations, parallax... and more!
A "hot corner" picker which displays the options in their corresponding corners using custom select. It also uses advanced attr() functions to get the option value and the if() function to define in which corner to place the option. See the full demo on @codepen.io codepen.io/cbolson/pen/...
One more Custom Select demo to round off the week. This displays the options as a tags list - nice and simple! See the full demo on @codepen.io : codepen.io/editor/cbols...
Chris Bolson reposted
The <select> element has been tough to style for decades. appearance: base-select changes that. We'll walk you through full CSS control, rich HTML options, and keeping it accessible — all while leveraging the power of the native element.
This has to be one of my favorite @codepen.io collections right now: codepen.io/collection/G... It contains my demos where I've been testing out the new customizable <select> element. With Safari 27 adding support, fully customizable select lists are starting to feel like a real possibility!
Yet another custom select demo based on the 2026 World Cup 😅 This one takes advantage of the optgroup element to display each group as a css grid cell block, along with normal grid responsiveness. See the demo on @codepen: codepen.io/editor/cbols...
⚽ Football Team Selector Pick a team and the formation reconfigures as players transition into their new positions. Team shirt colors update too. Built with custom select styling, anchor positioning, advanced attr() functions, and container style queries. See the full demo on @codepen.io
I also did a simpler version without the team selection that allows you to select between pre-defined formations using hidden radio buttons: codepen.io/editor/cbols...
⚽ Football Team Selector Pick a team and the formation reconfigures as players transition into their new positions. Team shirt colors update too. Built with custom select styling, anchor positioning, advanced attr() functions, and container style queries. See the full demo on @codepen.io
You can see the full demo here: codepen.io/editor/cbols...
This World Cup-themed selector presents teams as a rotating list of options rather than a traditional dropdown. Built using the latest experimental select customization features, with the native options list serving as a fallback where unsupported. Demo on @codepen.io codepen.io/editor/cbols...
A new #cssonly carousel demo built around the :scroll-* pseudo-elements. Using: – CSS anchor positioning for centered placement – container style queries to toggle between transition modes A fun experiment with some modern CSS features. See the demo on @codepen.io codepen.io/editor/cbols...
It makes my month when Alvaro picks one of my CodePen demos, thanks @alvaromontoro.com ! The one that Alvaro features in his April top 10 was slightly different than my usual demos as I had a go at some CSS art to help celebrate the Artemis 2 Moon Flyby.
10 Cool CodePen Demos – April 2026 alvaromontoro.com/10-cool-code... CSS Art (lots of CSS Art!), accordions, scroll-driven animations, components, JS games... and more! #css #html #javascript #webdev
Just another clock… but really an excuse to play with CSS anchor positioning to place time labels along expanding clock-hand rings. JS updates a few CSS custom properties, whilst CSS uses and display the values. The cheese color swapper was just an extra bit of fun. See the demo on @codepen.io
This circular color theme switcher uses hidden radio buttons and clip-path on the labels. See the full demo on @codepen.io codepen.io/cbolson/full...
A simple css scroll based animation to help celebrate the Artemis 2 crew reaching the furthest point mankind has travelled from earth 🚀 See the full demo on @codepen.io codepen.io/cbolson/full... #artemis
Chris Bolson reposted
For the past 3+ years, I have been posting a monthly "newsletter" with some cool CodePen demos published during that month. alvaromontoro.com/10-cool-code... For a change, I recorded a video talking about them and showing why I think they are cool: www.youtube.com/watch?v=KW91...
To celebrate the launch of Artemis II 🚀, I put together a #cssonly scroll-driven animation. Powered by animation-timeline: scroll — no JavaScript, just modern CSS. Still WIP, but already a fun experiment. Full demo on @codepen.io ✨ codepen.io/cbolson/full... #artemis
Chris Bolson reposted
10 Cool CodePen Demos from March alvaromontoro.com/10-cool-code... Really impressive CSS Art, even more impressive custom selectors, new feature showcases, electronic "dash battles", scroll-driven animations... and more! #css #html #javascript #webdev #codepen
Chris Bolson reposted
I've just relaunched CSS Demystified! Rebuilt from the ground up, on my own custom platform, and here to help you start writing CSS with confidence 😊 thecascade.dev/courses/css-...
More CSS anchor positioning fun! In this demo: – an indicator slides behind hovered avatars – team data snaps perfectly into a central octagon All tied together with a bit of corner-shape() magic. Pure CSS. Full demo on @codepen.io codepen.io/cbolson/pen/...
Arrowed nav links using just corner-shape(). Hover or focus to expand — pure CSS, zero JS. Full demo on @codepen.io codepen.io/cbolson/pen/...
This demo uses animation-timeline: scroll to smoothly zoom each card into the center as you scroll - powered by modern CSS. See the full demo on @codepen.io codepen.io/cbolson/pen/...
Chris Bolson reposted
After finally understanding @css-only.dev's demo for calculating the shortest paths between points, I was able to create this little spotlight effect. Pretty happy with the result! codepen.io/enbee81/deta...
Chris Bolson reposted
One day you're like "we should send a weekly newsletter about the cool stuff on @codepen.io and around". Then 500 weeks go by. 🎉 codepen.io/spark/500
Race to the 2025 F1 Drivers’ Championship 🏎️ This demo leans heavily on modern CSS: • advanced attr() functions • animation-timeline: scroll The race positions and data update as you scroll through the season - all driven by CSS. Full demo on @codepen.io codepen.io/cbolson/pen/...
CSS Daily 2026-03-07 Score: 73% | Time: 10:02 Such fun! Hopefully with practice I can improve on that percentage! cssdaily.dev