body.hide-title h1.entry-title, 
body.hide-title h1.wp-block-post-title {
  display: none;
}

body.hide-featured-image .post-thumbnail, 
body.hide-featured-image figure.wp-block-post-featured-image, 
body.hide-featured-image .entry-content > img.wp-post-image {
  display: none;
}