The specificity of :is() comes from its arguments

Useful to know

The pseudoclass :is() gathers alternative selectors in one position. Its specificity is determined by the strongest selector on the list, not just by the one who actually matched. [1]

Example: :is(.card, #featured) a includes a ID weight for the entire selection. This can make it more difficult to subsequently replace a style for links in a regular map. If the goal is a general rule with an easily changeable priority, consider :where(). Shortening a record should not hide a change in the behavior of the cascade.