an><span class="p">.</span><span class="nx">height</span> <span class="o">=</span> <span class="nb">window</span><span class="p">.</span><span class="nx">innerHeight</span><span class="p">;</span>
  <span class="p">}</span>

  <span class="c1">// add event listeners to specify when functions should be triggered</span>
  <span class="nb">window</span><span class="p">.</span><span class="nx">addEventListener</span><span class="p">(</span><span class="s1">'resize'</span><span class="p">,</span> <span class="nx