Using CSS pseudo-classes :is (previously :any and :matches) and :where, you can use comma to match multiple classes on any level. At the root level, :is(.abc, .xyz) and .abc, .xyz function almost identically. However, :is allows matching only a part of the selector without copying the whole selector multiple times. For example, if you want to match .root .abc .child and .root .xyz .child, you ...