Privacy

You can study without an account. Without one we collect no personal data. If you create an account we ask only for an email and an optional name. We never ask for a driver license number or Social Security number.

• Your progress (answers, mock exams, language) is stored in your own browser's local storage. You can export it or delete it at any time on the Progress page.
• If you create an account, we store your email address, an optional name, a password hash (or your Google account id if you sign in with Google), your sign-in sessions, and the study progress you choose to sync (answers, mock exam results, language and last chapter). Accounts are handled by our database provider, Neon (Managed Better Auth), in the United States. You can download everything we store on the Account page, or delete the account and all of its data there at any time. Accounts are for people aged 13 or older.
• To apply free usage limits we count mock exams and practice sets per account per day. Visitors without an account get a random trial id in a signed, first-party cookie (wa_g); it contains no personal information.
• If you buy a pass, payment is handled by Stripe. We receive the purchase record (plan, amount, time, Stripe payment id and the email you used) but never your card number. Stripe's privacy policy applies to the payment itself.
• Messages you send through the contact form (your email, topic and message) are stored so we can reply, and deleted on request.
• Once you have answered a question we set one first-party cookie, wa_r=1, so the home page can show your “welcome back” view. It holds no identifier or answers and is removed when you delete your data.
• When you submit a mock exam, the server scores it and may keep an anonymous record of which options were chosen for each question (no identifier, no IP address) to improve question quality.
• When you report a problem, we store the question id, category and your message. Please do not include personal information.
• Hosting providers may keep standard request logs (such as IP address) for security and operations.
• We do not show advertising.
• We do not use third-party tracking.
• Payments for voluntary support, if offered, are handled by the payment provider on its own page; we never see your card details.

隐私说明：无需账户即可学习。不注册时我们不收集个人信息；注册账户时仅需邮箱和可选的姓名。我们从不索取驾照号码或社会安全号码。学习进度保存在您的浏览器中，可随时导出或删除。交卷时服务器可能保存匿名作答记录用于改进题目质量；问题报告仅保存题号、类别和您的描述。