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HTML

            
              <!-- 
  Typically your custom element definitions would be 
  in a separate html file that you would import into
  other pages with the <link rel="import" /> tag.
  
  Note that the Polymer.register(this) call is only
  necessary to register the element with the Polymer
  polyfill library.
-->

<element name="greeting">
  <template>
    <style scoped>
      span { color:gray; }
    </style>
    <span>Simon says:</span>
    <q><content/></q>
  </template>
  <script>Polymer.register(this);</script>
</element>

<!--
  The main HTML for the page starts here.
-->

<greeting>Hello!</greeting>

            
          
!

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CSS

            
              
            
          
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JS

            
              
            
          
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