Cookie Policy

What is stored in your browser

Cookies are values a browser stores and can send with requests to a website. Local storage also saves values in the browser, but does not automatically attach them to requests. This policy covers both.

• Sign-in: the necessary __Host-btl-session cookie keeps you signed in for up to seven days. Signing out revokes that session and clears the cookie.
• Registration: the necessary __Host-btl-registration cookie connects verification to the browser where you started, for up to three hours and ten minutes. After verification it lets other open tabs identify the result. Password sign-in or sign-out clears it.
• Email link: the necessary __Host-btl-pending cookie remembers the verification link selected in this browser so refreshing can recover the page. It lasts for at most 70 minutes, including a brief period to check the result after verification. It does not extend link validity or sign you in by itself. Password sign-in or sign-out clears it.
• Password reset: the necessary __Host-btl-reset cookie remembers the selected reset link for up to 70 minutes, including ten minutes to check the result after the one-hour reset window. It does not sign you in or extend the reset deadline.
• Theme: btl-theme remembers the light or dark theme you select.
• Navigation: btl-nav-v1 remembers which menu links your account showed last time, such as whether you are signed in, so the next page can draw them immediately. It holds no name, email or account details, never grants access, and is corrected by our servers on every page and cleared when you sign out.
• Quiz progress: btl-quiz-v1:<lesson> remembers completed questions for each lesson. It is not sent to our servers.
• Privacy choice: btl-privacy-v1 records whether you allow optional analytics and when you made that choice. We ask again after 180 days.

The account cookies are first-party cookies that browser scripts cannot read. They support registration and sign-in even when you select Only Necessary. Theme, navigation, quiz progress, and privacy choice use first-party local storage. Theme, navigation, and quiz progress remain until you or your browser removes them. A saved privacy choice remains in storage until removed or replaced, but stops authorizing analytics after 180 days. You can clear all of them through your browser's site-data settings.

Cloudflare also delivers and protects this site. Its security features may use cookies when needed to check traffic or remember a security challenge. Those are separate from optional Web Analytics and cannot be switched off by our analytics setting. Blocking them in your browser may affect access to the site. Cloudflare describes these cookies and their durations in its cookie documentation.

Optional Cloudflare Web Analytics

When configured, Cloudflare Web Analytics helps us understand visits and page performance. Its browser script does not use cookies or local storage to track visitors. It reports information such as page paths, referring sites, browser and device categories, and page-load measurements. We do not add quiz answers or saved quiz progress to those reports.

We show the same prompt regardless of your country. Allow All enables optional analytics. Only Necessary leaves it off. Your selected theme and quiz progress support the features you use and are not used for tracking. We load the analytics script only after you choose Allow All. Choosing Only Necessary does not prevent you from using lessons or quizzes. If your browser sends Global Privacy Control, we keep optional analytics off. Development and preview sites do not load the analytics script.

Changing your choice

Use Cookie settings in the footer to change your choice about analytics. Withdrawing a previous allowance reloads the page to remove the loaded script and prevent further collection on subsequent page loads. It does not erase measurements already sent. Choices apply to this browser on this site, so make the same choice on other browsers or devices you use.

Without JavaScript or a saved allowance, our optional analytics script does not load. If your browser cannot save a preference, analytics stays off. This control does not prevent Cloudflare from processing the network requests needed to deliver and protect the website.

Advertising and future changes

We do not currently show advertising or use advertising trackers. If we introduce sponsorships or third-party advertising, we will identify paid placements and update our policies before introducing new data uses. Consent to analytics will not count as consent to advertising tracking.

Our Privacy Policy explains other information handling. For questions, contact [email protected].