403 Forbidden Error Block for React

Yes: it writes the admin's address to the clipboard, and a polite status line under the list says "Copied thessaly@nooklane.example. Nothing was sent." If the browser refuses (a page not served over HTTPS, or no permission) the line says so and asks you to select the address by hand. The button's own announcement is turned off so the page says it once. Nothing is emailed: the visitor pastes the address into their own mail.

From the typed constant ADMINS: a name, an address, initials and the last day each was active. "Active today", "Active yesterday" and "Active 5 days ago" are counted from the typed AS_OF date in UTC, never from the clock, so the page reads the same on the server and in every time zone. In your app, list the admins of the workspace the visitor tried to open, and think about whether each admin has agreed to be contacted this way; a short list of people who have is kinder than every admin there is.

The "403" is decoration (hidden from assistive technology) and the door, drawn in place of the zero, is a small greyscale SVG with no focusable parts. The sentence under the heading says "Error 403" in words and says what is wrong, so nothing depends on the picture.

No: a component can't. Send the real HTTP status from your server or framework, so crawlers, monitors and API clients see a 403 and not a 200 with an error drawn on it. Use 401 instead when the visitor isn't signed in at all.

Because the list is tall on a small screen and the way out should stay in reach. The button sits in a foot that is sticky at the bottom of the screen below the small breakpoint and falls back into the flow from there up, so the page has the one coloured button in both layouts, never two.

To #: point it at your wiki's home route. It's a Shine Button with render set to an a element and nativeButton={false}. The page never calls history.back(): a visitor who followed a shared link has no history to go back to.