Use position: sticky to create a CSS-only scroll-top link.
Topic: CSS
The oklch() color function enables using the P3 color space but more importantly allows color manipulations that retain perceived lightness.
Learn how to use Tailwind's group selector and arbitry variants to style an element's children.
Learn how to escape strings in JavaScript to use them safely as CSS selectors.
A quick note about Manuel Matuzović's discovery of Safari not being able to focus zero-size elements.