HTML First CSS
CSS can express presentation without a script that watches every interaction. Focus styles should remain visible for keyboard users.
Where to run this
This example changes a document. Open it in the HTML playground, then select Run code. It runs inside a separate preview.
A practical example
<style>button { padding: 12px 18px; } button:focus-visible { outline: 3px solid #17634c; outline-offset: 4px; }</style>
<button type="button">Check keyboard focus</button>
What happens
Tab to the button to see a clear focus ring.