```ts
// Button.stories.ts

import type { Meta, StoryObj } from '@storybook/web-components';

const meta: Meta = {
  component: 'demo-button',
};

export default meta;
type Story = StoryObj;

export const Primary: Story = {
  args: {
    background: '#ff0',
    label: 'Button',
  },
};

export const Secondary: Story = {
  args: {
    ...Primary.args,
    label: '😄👍😍💯',
  },
};

export const Tertiary: Story = {
  args: {
    ...Primary.args,
    label: '📚📕📈🤓',
  },
};
```