---
category: Content
---

# Rule

A hairline. It separates, and it is allowed only where the separation carries information:
between the items of a list that genuinely divide, or under the header.

There are no shadows and no borders around cards in this system. Separation comes from a
hairline or from a change of surface, and nothing else.

```jsx
<Rule />
```

Astro equivalent: `<hr class="rule">`.