css/.storybook/Button.js

import React from 'react'
import { storiesOf } from '@storybook/react'

storiesOf('Button', module)
  .add('btn', () => (
    <button className='btn'>Button</button>
  ))
  .add('btn-primary', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-primary'>Button</button>
      <button className='btn btn-primary hover'>hover</button>
      <button className='btn btn-primary focus'>focus</button>
      <button className='btn btn-primary selected'>selected</button>
      <button className='btn btn-primary disabled'>disabled</button>
    </div>
  ))
  .add('btn-secondary', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-secondary'>Button</button>
      <button className='btn btn-secondary hover'>hover</button>
      <button className='btn btn-secondary focus'>focus</button>
      <button className='btn btn-secondary selected'>selected</button>
      <button className='btn btn-secondary disabled'>disabled</button>
    </div>
  ))
  .add('btn-danger', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-danger'>Button</button>
      <button className='btn btn-danger hover'>hover</button>
      <button className='btn btn-danger focus'>focus</button>
      <button className='btn btn-danger selected'>selected</button>
      <button className='btn btn-danger disabled'>disabled</button>
    </div>
  ))
  .add('btn-outline', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-outline'>Button</button>
      <button className='btn btn-outline hover'>hover</button>
      <button className='btn btn-outline focus'>focus</button>
      <button className='btn btn-outline selected'>selected</button>
      <button className='btn btn-outline disabled'>disabled</button>
    </div>
  ))
  .add('btn-blue', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-blue'>Button</button>
      <button className='btn btn-blue hover'>hover</button>
      <button className='btn btn-blue focus'>focus</button>
      <button className='btn btn-blue selected'>selected</button>
      <button className='btn btn-blue disabled'>disabled</button>
    </div>
  ))
  .add('btn-purple', () => (
    <div className='p-4 d-flex flex-justify-between'>
      <button className='btn btn-purple'>Button</button>
      <button className='btn btn-purple hover'>hover</button>
      <button className='btn btn-purple focus'>focus</button>
      <button className='btn btn-purple selected'>selected</button>
      <button className='btn btn-purple disabled'>disabled</button>
    </div>
  ))