# Functional pseudo-class

A pseudo-class that takes selectors in brackets, like :not().

## What is a **functional pseudo-class**?

A **functional pseudo-class** takes selectors in brackets, like `:is()`, `:not()` or `:has()`.

```css
button:not(:disabled):hover { background: darkblue; }
```

Level: Freelancer · [More CSS terms at this level](https://www.ask-codey.com/glossary/subjects/css/freelancer)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/functional-pseudo-class