ashserrao/react-task-planner ? reverse-engineered prompt

Build me a simple task planner app for time management.

I want a clean React app where someone can add things they need to do, give each item a title and maybe a time or date, then keep track of what is planned for the day. It should let people mark tasks as done, edit them if plans change, and remove them when they are no longer needed. A clear layout would be great, with the current list easy to scan and a way to tell what is urgent, what is later, and what is already finished.

Please make it look polished and easy to use, with a responsive design so it works well on desktop and mobile. If it helps, use current best practices and look up any recent docs online. Also make sure it runs cleanly with the existing React project setup and is ready to start with a simple npm start.