In CSS, pseudo-classes are used to style elements based on their state or position in the document. They allow developers to target specific elements based on user interactions, such as hovering over a link or selecting a form input.
The :is() pseudo-class is a CSS selector function that allows developers to write complex selectors with less code. It lets you group together multiple selectors, separated by commas, and apply styles to all elements that match any of those selectors. This helps to simplify your code and make it more readable.
The :where() pseudo-class is similar to :is(), but it doesn't create a new selector group. Instead, it allows you to specify a list of selectors that are all applied to the same element. This can be useful when you want to apply styles to elements that match any of several selectors, but don't want to group them together.