Fix Lightbox trigger BUTTON visibility issue on an Image lightbox when Picture Element is enabled

plugins/webp-uploads/picture-element.php

@@ -168,3 +168,26 @@
 		$image
 	);
 }
+
+/**
+ * Adds CSS to make Lightbox trigger BUTTON visible on an Image lightbox when Picture Element is enabled.
+ *
+ * @since n.e.x.t
+ */
+function webp_make_lightbox_trigger_button_visible(): void {
+	if ( has_filter( 'render_block_core/image', 'block_core_image_render_lightbox' ) ) {
+		echo '<style> .wp-lightbox-container > picture + button { opacity: 1 } </style>';
+	}
+}
+
+/**
+ * Add an action to wp_footer conditionally for lighbox trigger button visibility.
+ *
+ * @since n.e.x.t
+ */
+function webp_add_footer_action_for_lightbox_button_visibility(): void {
+	if ( webp_uploads_is_picture_element_enabled() ) {
+		add_action( 'wp_footer', 'webp_make_lightbox_trigger_button_visible' );
+	}
+}
+add_action( 'init', 'webp_add_footer_action_for_lightbox_button_visibility' );