Code in an answer, a tool's output or a diff: mono on a quiet surface with a 32px header that holds the file name and a Copy button. tsx, ts, jsx and js are highlighted in the foreground's tones only (strings take a hint of the accent text), a diff shows a + in success and a - in danger on a faint band with hidden "Added" and "Removed" words, line numbers sit in a gutter that is not selected or copied, and long lines scroll sideways inside a focusable, labelled block. Static.
pnpm dlx shadcn@latest add "https://littmd.vercel.app/r/code-block.json"