⚙️ Setup Required
To enable accounts & history, open this file in a text editor and replace the two placeholders near the top of the <script> section:
YOUR_SUPABASE_URL → your project URL (e.g. https://xxxx.supabase.co)
YOUR_SUPABASE_ANON_KEY → your project's anon/public key
Both are found in your Supabase dashboard → Project Settings → API.
Also run the SQL in the comments to create the grades table.