Privacy Policy

What we collect. The Site works without an account. Standard web server logs (IP address, user agent, pages requested, timestamps) are kept briefly for security and capacity planning. Preferences you set (interface language, theme, view mode, ★ saved cards) and your course progress are stored in your own browser (cookies/localStorage), not on our servers, until you choose to save progress by email.

Progress saving (optional). If you enter your email to save progress, we store that email with your progress data (which lessons and quiz scores you've completed) and a random token so your browser can sync automatically. There is no password: anyone entering the same email can restore the progress stored under it: by design, since it contains nothing sensitive. Quiz attempts are also logged (score and course only) to monitor question quality. You can request deletion at any time via Contact.

What we store server-side. Contact-form messages and update-list emails are stored to respond and to send the updates you requested. We do not sell or share this information.

Ask Quantum. Questions typed into Ask Quantum are processed to generate an answer and are subject to a per-connection rate limit; questions are not linked to an identity.

Cookies. First-party cookies/localStorage are used for the preferences and progress described above, plus the Google Analytics measurement cookies described under Analytics below.

Analytics (Google Analytics 4). We use Google Analytics to count visits and see which pages are useful. It runs under Google Consent Mode: advertising signals (ad storage, ad user data, ad personalization) are denied by default, and Google states that Analytics 4 does not log or store IP addresses in its reports. If you prefer not to be counted, use the Google Analytics opt-out browser add-on or block cookies for this Site in your browser settings.

Advertising (Google AdSense). If advertising is enabled on this Site, third-party vendors, including Google, use cookies to serve ads based on your prior visits to this and other websites. Google's use of advertising cookies (such as the DoubleClick cookie) enables it and its partners to serve personalized ads. You may opt out of personalized advertising at Google Ads Settings, and learn more at Google's advertising policies. Where required, ad personalization is subject to your consent choices.

Third-party links. News headlines and resource links (including YouTube channels) go to external publishers; their privacy practices are their own.

Changes. This policy may be updated; material changes will be reflected on this page.