Privacy policy

Who runs this site

CellKata is run by [operator name, address, contact email]. If you have questions about your data, use the contact form.

Without an account

You can use every lesson without signing up. Your progress, points and settings are then kept only in your browser's storage on your device; we don't receive them. The keys start with fp-, and the light or dark theme is stored as theme. Clearing your browser's site data removes them.

With an account

If you sign in, we store:

• your email address, to sign you in (by email link, or Google sign-in if you choose it);
• a display name (the first word of your Google name, or "Learner" with a number) and your language and formula settings;
• the answers you check: the exercise, the formula you typed, whether it was right, and when;
• your lesson progress, points and streak.

We use your answers to run the site (progress, points) and, combined across all learners, to see which mistakes are common in each language and write better hints.

What others can see

Today's leaderboard shows the display names and points of signed-in learners who scored today. Nothing else about you is public.

Contact form

When you send a message, we store your name, email address, message and the page language, and your account if you're signed in, so we can reply.

Cookies and tracking

There are no ads, no advertising or tracking cookies and no third-party analytics. If you sign in, a cookie keeps you signed in; it is necessary for the account to work. Fonts are served from this site, not from a third party.

Services we use

Accounts, progress and contact messages are stored with Supabase [region]. The site is hosted by [hosting provider]. These providers process data only on our behalf.

How long we keep it

Account data is kept until you delete your account or ask us to. Contact messages are kept for [period] after the conversation ends.

Your rights

You can ask to see, correct, export or delete your data at any time through the contact form. If you're in the EU or UK, you can also complain to your data protection authority.

Children

[Minimum age and parental consent rules, to be decided.]

Changes

If this policy changes, the date at the top changes too. Important changes will be announced on the site.