CSS :is() pseudo-class

The :is pseudo-class takes a list of selectors and selects any elements that matches the selectors in that list. Its useful to compact large selectors.

Take this example:

header h2,
nav h2,
article h2 {
  color: black;
}

Can be written as:

is:(header, nav, article) h2 {
  color: black;
}

Learn More

It's worth noting there is a difference between :is and :where() when it comes to specificity value. Detailed explanations:

• MDN Docs
• Simpler CSS Selectors With :is()
• Using :is() in complex selectors selects more than you might initially think