Flexbox Froggy teaches CSS Flexbox through a game where you help frogs reach lily pads by writing flexbox properties. Each level introduces a new property or value, and the visual feedback is immediate. The challenges progress from simple alignment to complex wrapping and ordering. There are 24 levels in total.

It is one of the most effective ways to learn flexbox because it turns abstract properties into something you can see working. The same team made Grid Garden for CSS Grid. Developers who have struggled with centering or alignment often find that a few minutes with these games clarifies concepts that documentation alone did not. It is free and works in any browser.