Learn CSS gets its biggest update since 2021

web.dev has refreshed its Learn CSS course, adding nine new modules and revising existing content throughout. The update brings the course in line with where CSS stands in 2025, four years after the original launch.

Originally published in 2021, Learn CSS was the first course in what has since grown to an 11-course library on fundamental web development topics. While the core material aged well, major CSS features that developers now rely on simply didn't exist—or weren't stable—when the course first went live. The most telling example: container queries were absent because no browser supported them at the time, yet the feature reached Baseline Widely available just last month.

Given the thousands of people using the material monthly, the new modules cover features that have shipped and proven useful since the original release:

Teaching features you can actually use

New material is deliberately scoped to features at or near the Baseline Newly available threshold, meaning they're practical to use now or in the very near future. That's why anchor positioning and view transitions for single-page apps made the cut: both are part of Interop 2025 and expected to reach Baseline shortly. Every module includes explicit browser support information.

The refresh was written by the team at Oddbird, with editing and production by Jeremy Wagner. The original 2021 course was authored by Andy Bell with contributions from Una Kravets, Adam Argyle, Rachel Andrew, Emma Twersky, Camden Bickel, and Kevin Lozandier.