Fade in.
A quiet arrival from transparent to visible.
See the movement
One intentional triggerPlayback starts only when you request it. Stop returns to the still illustration.
What it does
Opacity increases without changing the element’s position. A fade is useful when content should arrive without implying that it traveled from somewhere else.
Timing curve
ease-outDefault duration350ms
RepetitionOnce per trigger
Make the motion useful
Choose an effect that supports the component’s purpose. Keep the final state clear, preserve focus and reading order, and pair important feedback with a visible message.
CSS animation reference