Privacy Policy

1. Information We Collect

We believe in collecting only what is absolutely necessary for the service to function.

• Account Information: If you choose to create an account to sync your progress, we collect your email address and an optional display name.
• Learning Progress: When logged in, your progress (which concepts you've completed) is synced to our database. This is stored as an opaque block of data.

2. How We Use Your Information

We use your email exclusively for authentication (sending secure login links) and critical account notifications. We do not sell your data, and we do not use your email for marketing.

3. Analytics

We use analytics to understand which concepts are most helpful and where learners get stuck. Our analytics are strictly cookieless. We do not set tracking cookies or track you across other websites. We only measure aggregate usage of our own site to improve the content.

4. Data Deletion

You can permanently delete your account and all associated progress data at any time from your Account settings. Deletion is instantaneous and irreversible.

5. Contact Us

If you have questions about this privacy policy, please reach out via our Contact page.