It would also help to mention that -- as of now in 2022 -- you shouldn't rely on it for crApple products as it's still hidden away as an experimental feature.

https://caniuse.com/?search=focus-visible

Made all the more pathetic by how FF has had this as -moz-focusring since 2011. and when the announcement of the name change was made just last year, FF had it deployed in what? A week?