add page slug to body class: http://www.wpbeginner.com/wp-themes/how-to-add-page-slug-in-body-class-of-your-wordpress-themes/

body-class.php

<?php 
  // Page Slug Body Class 
  function add_slug_body_class( $classes ) {
    global $post;
    if ( isset( $post ) ) {
      $classes[] = $post->post_type . '-' . $post->post_name;
    }
    return $classes;
  }
  
add_filter( 'body_class', 'add_slug_body_class' );