By default stories are rendered inline. For web components that is usually fine as they are style encapsulated via shadow dom. However when you have a style tag in you template it might be best to show them in an iframe.

To always use iframes you can set

addParameters({
  docs: {
    inlineStories: false,
  },
});

or add it to individual stories.

<Story inline={false} />

More resources

Want to learn more? Here are some more articles on Storybook Docs:

References: DocsPage / MDX / FAQ / Recipes / Theming / Props
Announcements: Vision / DocsPage / MDX / Framework support
Example: Storybook Design System