ElevatedButton(

Shape-shifting (complete)

Here’s the example with the completed changes you’ve made—run the code
and click the Change button to trigger the animation. Notice that each time
you click the Change button, the shape animates to its new values
for margin, borderRadius, and color.

Using animation curves

The preceding examples show how implicit animations allow you to animate
changes in values for specific widget properties, and how the
duration parameter allows you to set the amount of time an
animation takes to complete. Implicit animations also allow you to
control changes to the rate of an animation within the duration.
The parameter you use to define this change in rate is curve.

linear animation curve by default.
Add a

shape-shifting complete
and watch how the animation changes when you pass the

easeInOutBack constant for

{container5 → container6}/lib/main.dart