擬似クラス Pseudo-classes

Action = :hover, :active, :focus, :focus-visible, :focus-within

Input = :autofill, :checked, :disabled, :valid, :invalid, :user-valid, :user-invalid, :required, … etc.

Display = :fullscreen, :modal, :picture-in-picture

Language = :dir(), :lang()

Location = :link, :visited, :target, … etc.

Resource = :playing, :paused

CustomStateSet = custom states for web components

… etc