title: how to fix error Does not use passive listeners to improve scrolling performance (Lighthouse Report)
body: <p>A recent Lighthouse Report flagged the following issue.</p>
  <p>&quot;Does not use passive listeners to improve scrolling performance&quot;</p>
  <p>How do I resolve this issue?.</p>
  <pre><code>( function( document, window, undefined ) {
  var form = document.getElementById( 'form-wrapper' ),
  toggle = document.querySelector( '.search-toggle' ),
  close = document.getElementById( 'search-close' ),
  click = 'ontouchstart' in window ? 'touchstart' : 'click';
  toggle.addEventListener( click, toggleSearchForm );
  close.addEventListener( click, closeSearchForm );
  
  function toggleSearchForm() {
      if ( form.classList.contains( 'is-visible' ) ) {
          closeSearchForm();
      } else {
          form.classList.add( 'is-visible' );
          form.querySelector( '.search-field' ).focus();
      }
  }
  function closeSearchForm() {
      form.classList.remove( 'is-visible' );
  }
  
  // Press ESC key close search form.
  document.addEventListener( 'keyup', function( event ) {
      if ( 27 === event.keyCode ) {
          closeSearchForm();
      }
  } );
  
  // Sticky share button for single posts. Applied only for large screens and icon style.
  if ( window.innerWidth &gt;= 1200 &amp;&amp; 'undefined' !== typeof StickySidebar ) {
      var adminBarHeight = document.body.classList.contains( 'admin-bar' ) ? 32 : 0,
          sharedaddy = new StickySidebar( '.entry-body .sharedaddy', {
              containerSelector: '.entry-body',
              innerWrapperSelector: '.sd-social-icon',
              topSpacing: adminBarHeight
          } );
  }
  </code></pre>
  <p>} )( document, window );</p>