diegonatalo/fitlog ? reverse-engineered prompt

Build me a fitness tracking web app called FitLog where users can create and edit workout routines, add exercises to each routine, and log sets, reps, and weights as they train. I want a clean interface that makes it easy to see today’s workout in progress, browse all saved routines, and check a history of past sessions so people can follow their progress over time.

Please include search and filtering for exercises by muscle group, plus basic add, edit, and delete actions for workouts and exercises. Save everything locally so the data stays there when the page is refreshed, and make the whole thing work well on mobile too. Use a simple modern design, and organize the app so it feels smooth and easy to use. If you need to look up current docs online for anything, go ahead.