storybook/docs/snippets/svelte/button-story-component-args-primary.js.mdx

```js
// Button.stories.js

import Button from './Button.svelte';

export default {
  title: 'Button',
  component: Button,
  argTypes: {
    backgroundColor: { control: 'color' },
  },
  args: {
    // Now all Button stories will be primary.
    primary: true,
  },
};
```