render((
  <Router history={browserHistory}>
    <Route path="/" component={StartPage}>
      <IndexRoute component={Index}/>
      <Route path="/signup" component={Signup}/>
      <Route path="/login" component={Login}/>
      <Route path="app" component={App}>
        <Route path="projects" component={Projects}/>
        <Route path=":user" component={Home}/>
      </Route>
    </Route>
  </Router>
), document.getElementById('root'));

<link rel="stylesheet" href="/style.css">

<script src="/build/bundle.js"></script>