

<link rel="import" href="../bower_components/google-codelab-elements/google-codelab-elements.html">
<link rel="import" href="../bower_components/google-youtube/google-youtube.html">
<style is="custom-style">
:root {
  --google-material-blue-600: #1A73E8;
  --google-material-blue-800: #185ABC;
  --google-material-green-600: #1E8E3E;
  --google-material-grey-900: #212124;
  --google-material-grey-800: #3C4043;
  --google-material-grey-700: #5f6368;
  --google-material-grey-600: #80868B;
  --google-material-