First line: the Aproject action button — terracotta `primary` for the one key action, outlined `secondary` / chrome-free `ghost` for the rest.

```jsx
<Button variant="primary" icon="Edit">Новый чат</Button>
<Button variant="secondary" icon="Share">Поделиться</Button>
<Button variant="ghost" size="sm">Отмена</Button>
<Button variant="danger" icon="Trash">Удалить</Button>
<Button variant="primary" iconRight="ArrowRight" block>Попробовать бесплатно</Button>
```

Notes
- Sizes: `sm` (32px), `md` (38px, default), `lg` (44px — marketing CTAs).
- Use exactly one `primary` per surface. `danger` is reserved for destructive confirmation.
- Pass only `icon` and no children for a square icon-only button — but prefer `IconButton` for toolbar glyphs.