Nothing you do on this site is sent anywhere. There is no account to make, no form to fill in, no analytics script, no advertising, and no third-party request of any kind — the pages, the stylesheet, the fonts and the one script all come from this domain.
What is stored, and where
One thing: your colour theme, written to this browser’s local storage under this site’s own key. It never leaves the browser, it is not readable by any other site on the network, and clearing your site data removes it. If you never touch the theme picker, nothing is stored at all.
Following a link off this site
This site’s whole purpose is to send you to another one. Every site on the network is run by the same people under the same policy, so the answer does not change when you arrive — but each of them states its own, and none of them is reached by a redirect that could carry anything about you along.
Server logs
Pages are served from a content-delivery network, which keeps the ordinary operational request logs any web server keeps. They are not joined to anything, not used to profile anyone, and not shared.