CSS Transitions and Animations: A Production Playbook
Smooth motion makes interfaces feel intentional. Here is how I structure transitions and keyframe animations that perform well and stay maintainable. Motion is the difference between an interface that feels alive and one that feels mechanical. But motion done poorly. too slow, too bouncy, animating the wrong properties. feels worse than no motion at all. Over years of building production interfaces, I have settled on a small set of principles that keep animations smooth and maintainable. I want to walk through them with the specific mistakes I made along the way. The project that taught me the most was a drag-and-drop kanban board. Cards needed to animate when dragged, when dropped, when reordered, and when new cards appeared. Getting all of that right without jank took three iterations. The first version was a JavaScript-heavy mess that stuttered on mobile. The final version was almost entirely CSS transitions and keyframes, smooth at 60fps even on a 2018 iPhone. Transitions for State Changes Transitions are for changes between states. hover, focus, active, class toggles. They interpolate from the current value to the new one over a duration. The most common mistake I see…