Corner radii, in pixels: the card's as the site's cards
(--radius-xl), the images' as its thumbnails (--radius-md), the
buttons' as its buttons (--radius-lg), the pills' as its badges
(--radius-sm). The avatars' is the email's own, since the site rounds
them with a literal 50% that some styles square.
Usage
import { type EmailStyle } from "api/mail/styles.ts";