Transitioning specific properties and `display` property behavior.
You can transition multiple specific properties like `width` and `opacity` using `transition-[width,opacity]`. However, properties like `display` cannot be transitioned. Changes to `display` are always instant.
Width and opacity transition smoothly.
GOTCHA: `display` Property Does Not Transition
The change from `display: none` to `display: block` is instant, not smooth, regardless of transition utilities.