Centered paper-tabs example

paper-tabs.html

<paper-toolbar id="mainToolbar">
  <!-- Space to the Left -->
  <span class="flex"></span>

  <!-- Tabs -->
  <paper-tabs id="mainTabs" attr-for-selected="data-route" selected="{{route}}">
    <paper-tab data-route="home" href="/" on-click="onDataRouteClick">Home</paper-tab>
    <paper-tab data-route="videos" href="/videos" on-click="onDataRouteClick">Videos</paper-tab>
    <paper-tab data-route="photos" href="/photos" on-click="onDataRouteClick">Photos</paper-tab>
    <paper-tab data-route="contact" href="/contact" on-click="onDataRouteClick">Contact</paper-tab>
  </paper-tabs>
  
  <!-- Space to the Right -->
  <span class="flex"></span>
  
</paper-toolbar>