title: Add body class to node in Drupal 8
body: <p>I am experimenting with Drupal 8.  I've created a local sandbox site and created a custom theme and a custom front page using Twig (page--front.html.twig).  I want to add some custom CSS that just targets the front page and I am used to targeting the body.page-node-x (Drupal 7).  In Drupal 8 I am having issues adding a body class to this custom page.  The only body classes I am seeing are toolbar-tray-open toolbar-fixed toolbar-horizontal.   </p>