Setup Instructions

1. Go to console.firebase.google.com
2. Create a new project (free Spark plan works)
3. Click Authentication → Enable Google sign-in
4. Click Firestore Database → Create database (production mode)
5. Go to Project Settings → Your Apps → Add Web App
6. Copy the firebaseConfig object values
7. Open this HTML file in a text editor and paste them into FIREBASE_CONFIG near the top of the <script> tag

rules_version = '2'; service cloud.firestore { match /databases/{db}/documents { match /users/{userId} { allow read, write: if request.auth.uid == userId; } } }

Once configured, reload this page and sign in with Google. Your data will sync across all devices automatically.