orizontal start-justified layout meta">
              <div class="difficulty">
                Difficulty: <difficulty-indicator difficulty="[[difficulty]]"></difficulty-indicator>
              </div>
              <div class="duration">
                Duration: <span class="duration__value">[[duration]] min</span>
              </div>
            </div>
          </div>
        </a>
      </div>
    </paper-card>

  </template>

  <script>

    Polymer({

      is: 'codelabs-card',

      properties: {
 