app.template.html

<!-- app.template.html -->
<div>
  <my-top-bar on-reset-clicked="resetGame"></my-top-bar>
  <my-top-message time="{{currentTime}}"></my-top-message>
  <my-cards cards="{{cards}}" on-card-flipped="startGame" on-all-cards-matched="stopGame"></my-cards>
  <template is="dom-if" if="{{isGameCompleted}}">
      <my-pop-up-modal time="{{currentTime}}" on-reset-clicked="resetGame"></my-pop-up-modal>
  </template>
</div>