# Scroll timeline

Ties animation progress to how far an area has scrolled.

## What is a **scroll timeline**?

A **scroll timeline** ties an animation's progress to how far a scroll area has been scrolled, from top to bottom.

```css
.progress-bar { animation-timeline: scroll(root block); }
```

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

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/scroll-timeline