phsl / new-api

- Add greetingVisible state to control animation trigger
- Implement fade-in effect with 1-second smooth transition
- Set 100ms delay before animation starts
- Apply opacity transition from 0 to 1 using ease-in-out timing
- Enhance user experience with smooth visual feedback on page load

The greeting message now appears with an elegant fade-in animation,
transitioning from transparent to fully visible over 1 second,
providing better visual appeal and user engagement.