I need a single, clean Flutter code-base that compiles to Android, iOS, and a responsive Web app. The project’s purpose is to host my own mock-test content later, so the build must be ready for data I will upload through Firebase after hand-over. Core features to wire up • Mock Test engine – timed and untimed modes that pull questions, options, answers and explanations from Firestore placeholders. • User authentication – allow sign-up/sign-in with either email/password or verified mobile number, using Firebase Auth. • Progress tracking – capture attempts, scores and time spent, then surface a simple history page and per-test summary stored in Firestore. Technical expectations – Flutter 3.x with null safety, adaptive layout for phone, tablet and desktop browsers. – Firebase integration (Auth, Cloud Firestore, Cloud Functions if needed, and basic Analytics hooks). – State management with Provider, Riverpod or Bloc—your choice, as long as it is clearly documented. – Clean folder structure and comments so I can extend questions, subjects and UI text myself. Deliverables 1. Source code for the Flutter project, ready to run with a fresh Firebase project ID. 2. Release-ready Android APK/AAB, iOS archive, and deployed web build (can be hosted on Firebase Hosting or a build folder I can upload elsewhere). 3. A brief README that explains environment setup, Firebase config steps, and how to add new mock-test data. Acceptance I will run the builds on all three platforms, create a user with email and with phone number, take a sample test, and see the result reflected in the progress page. Once those checkpoints pass and code is cleanly organised, the job is complete.