layout.js

import React from 'react'
import 'foundation-sites/dist/css/foundation.css'

import TopBar from './TopBar'

class Layout extends React.Component {
  render () {
    <div className='container'>
      <TopBar />
      {this.props.children}
    </div>
  }
}

export default Layout

minirouter.js

import React from 'react'
import ReactDOM from 'react-dom'

import Layout from './Layout'
import Home from './Home'
import Submit from './Submit'
import './index.css'

const router = {
  '': <Home />,
  'submit': <Submit />
}

window.onhashchange = renderCurrentRoute
renderCurrentRoute()

function renderCurrentRoute () {
  const hash = window.location.hash.substr(1)
  const component = router[hash] || router['']

  ReactDOM.render(
    <Layout>{component}</Layout>,
    document.getElementById('root')
  )
}