Modal for focused tasks — add credits, agent detail, confirm destructive action.

```jsx
<Dialog open={open} onOpenChange={setOpen}>
  <DialogContent width={480}>
    <DialogHeader><DialogTitle>Add credits</DialogTitle><DialogDescription>Credits never expire.</DialogDescription></DialogHeader>
    <Input placeholder="$50" />
    <DialogFooter><Button variant="ghost" onClick={()=>setOpen(false)}>Cancel</Button><Button>Add credits</Button></DialogFooter>
  </DialogContent>
</Dialog>
```

Escape and scrim click both close. 16px radius (rounded-2xl), hairline border, shadow-2xl.