p_styles->registered[ $style['handle'] ]->src = false;
			if ( empty( $wp_styles->registered[ $style['handle'] ]->extra['after'] ) ) {
				$wp_styles->registered[ $style['handle'] ]->extra['after'] = array();
			}
			array_unshift( $wp_styles->registered[ $style['handle'] ]->extra['after'], $style['css'] );

			// Add the styles size to the $total_inline_size var.
			$total_inline_size += (int) $style['size'];
		}
	}
}

/**
 * Makes URLs relative to the WordPress installation.
 *
 * @since 5.9.0
 * @access private
 *
 * @param string $css            The CSS to make URLs relative to the WordPress installation.
 * @param string $stylesheet_url The URL to the stylesheet.
 *
 * @return string The CSS with URLs made relative to the WordPress installation.
 */
function _wp_normalize_relative_css_links( $css, $stylesheet_url ) {
	return preg_replace_callback(
		'#(url\s*\(\s*[\'"]?\s*)([^\'"\)]+)#',
		static function ( $matches ) use ( $stylesheet_url ) {
			list( , $prefix, $url ) = $matches;

			// Short-circuit if the URL does not require normalization.
			if (
				str_starts_with( $url, 'http:' ) ||
				str_starts_with( $url, 'https:' ) ||
				str_starts_with( $url, '/' ) ||
				str_starts_with( $url, '#' ) ||
				str_starts_with( $url, 'data:' )
			) {
				return $matches[0];
			}

			// Build the absolute URL.
			$absolute_url = dirname( $stylesheet_url ) . '/' . $url;
			$absolute_url = str_replace( '/./', '/', $absolute_url );

			// Convert to URL related to the site root.
			$url = wp_make_link_relative( $absolute_url );

			return $prefix . $url;
		},
		$css
	);
}

/**
 * Function that enqueues the CSS Custom Properties coming from theme.json.
 *
 * @since 5.9.0
 */
function wp_enqueue_global_styles_css_custom_properties() {
	wp_register_style( 'global-styles-css-custom-properties', false );
	wp_add_inline_style( 'global-styles-css-custom-properties', wp_get_global_stylesheet( array( 'variables' ) ) );
	wp_enqueue_style( 'global-styles-css-custom-properties' );
}

/**
 * Hooks inline styles in the proper place, depending on the active theme.
 *
 * @since 5.9.1
 * @since 6.1.0 Added the `$priority` parameter.
 *
 * For block themes, styles are loaded in the head.
 * For classic ones, styles are loaded in the body because the wp_head action happens before render_block.
 *
 * @link https://core.trac.wordpress.org/ticket/53494.
 *
 * @param string $style    String containing the CSS styles to be added.
 * @param int    $priority To set the priority for the add_action.
 */
function wp_enqueue_block_support_styles( $style, $priority = 10 ) {
	$action_hook_name = 'wp_footer';
	if ( wp_is_block_theme() ) {
		$action_hook_name = 'wp_head';
	}
	add_action(
		$action_hook_name,
		static function () use ( $style ) {
			$processor = new WP_HTML_Tag_Processor( '<style></style>' );
			$processor->next_tag();
			$processor->set_modifiable_text( $style );
			echo "{$processor->get_updated_html()}\n";
		},
		$priority
	);
}

/**
 * Fetches, processes and compiles stored core styles, then combines and renders them to the page.
 * Styles are stored via the style engine API.
 *
 * @link https://developer.wordpress.org/block-editor/reference-guides/packages/packages-style-engine/
 *
 * @since 6.1.0
 *
 * @param array<string, bool> $options {
 *     Optional. An array of options to pass to wp_style_engine_get_stylesheet_from_context().
 *     Default empty array.
 *
 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules.
 *                          Default false.
 *     @type bool $prettify Whether to add new lines and indents to output.
 *                          Default to whether the `SCRIPT_DEBUG` constant is defined.
 * }
 */
function wp_enqueue_stored_styles( $options = array() ) {
	// Note: Styles printed at wp_footer for classic themes may still end up in the head due to wp_load_classic_theme_block_styles_on_demand().
	$is_block_theme   = wp_is_block_theme();
	$is_classic_theme = ! $is_block_theme;

	/*
	 * For block themes, this function prints stored styles in the header.
	 * For classic themes, in the footer.
	 */
	if (
		( $is_block_theme && doing_action( 'wp_footer' ) ) ||
		( $is_classic_theme && doing_action( 'wp_enqueue_scripts' ) )
	) {
		return;
	}

	$core_styles_keys         = array( 'block-supports' );
	$compiled_core_stylesheet = '';
	$style_tag_id             = 'core';
	// Adds comment if code is prettified to identify core styles sections in debugging.
	$should_prettify = isset( $options['prettify'] ) ? true === $options['prettify'] : defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG;
	foreach ( $core_styles_keys as $style_key ) {
		if ( $should_prettify ) {
			$compiled_core_stylesheet .= "/**\n * Core styles: $style_key\n */\n";
		}
		// Chains core store ids to signify what the styles contain.
		$style_tag_id             .= '-' . $style_key;
		$compiled_core_stylesheet .= wp_style_engine_get_stylesheet_from_context( $style_key, $options );
	}

	// Combines Core styles.
	if ( ! empty( $compiled_core_stylesheet ) ) {
		wp_register_style( $style_tag_id, false );
		wp_add_inline_style( $style_tag_id, $compiled_core_stylesheet );
		wp_enqueue_style( $style_tag_id );
	}

	// Prints out any other stores registered by themes or otherwise.
	$additional_stores = WP_Style_Engine_CSS_Rules_Store::get_stores();
	foreach ( array_keys( $additional_stores ) as $store_name ) {
		if ( in_array( $store_name, $core_styles_keys, true ) ) {
			continue;
		}
		$styles = wp_style_engine_get_stylesheet_from_context( $store_name, $options );
		if ( ! empty( $styles ) ) {
			$key = "wp-style-engine-$store_name";
			wp_register_style( $key, false );
			wp_add_inline_style( $key, $styles );
			wp_enqueue_style( $key );
		}
	}
}

/**
 * Enqueues a stylesheet for a specific block.
 *
 * If the theme has opted-in to load block styles on demand,
 * then the stylesheet will be enqueued on-render,
 * otherwise when the block inits.
 *
 * @since 5.9.0
 *
 * @param string                                   $block_name The block-name, including namespace.
 * @param array<string, string|string[]|bool|null> $args       {
 *     An array of arguments. See wp_register_style() for full information about each argument.
 *
 *     @type string           $handle The handle for the stylesheet.
 *     @type string|false     $src    The source URL of the stylesheet.
 *     @type string[]         $deps   Array of registered stylesheet handles this stylesheet depends on.
 *     @type string|bool|null $ver    Stylesheet version number.
 *     @type string           $media  The media for which this stylesheet has been defined.
 *     @type string|null      $path   Absolute path to the stylesheet, so that it can potentially be inlined.
 * }
 */
function wp_enqueue_block_style( $block_name, $args ) {
	$args = wp_parse_args(
		$args,
		array(
			'handle' => '',
			'src'    => '',
			'deps'   => array(),
			'ver'    => false,
			'media'  => 'all',
		)
	);

	/**
	 * Callback function to register and enqueue styles.
	 *
	 * @param string $content When the callback is used for the render_block filter,
	 *                        the content needs to be returned so the function parameter
	 *                        is to ensure the content exists.
	 * @return string Block content.
	 */
	$callback = static function ( $content ) use ( $args ) {
		// Register the stylesheet.
		if ( ! empty( $args['src'] ) ) {
			wp_register_style( $args['handle'], $args['src'], $args['deps'], $args['ver'], $args['media'] );
		}

		// Add `path` data if provided.
		if ( isset( $args['path'] ) ) {
			wp_style_add_data( $args['handle'], 'path', $args['path'] );

			// Get the RTL file path.
			$rtl_file_path = str_replace( '.css', '-rtl.css', $args['path'] );

			// Add RTL stylesheet.
			if ( file_exists( $rtl_file_path ) ) {
				wp_style_add_data( $args['handle'], 'rtl', 'replace' );

				if ( is_rtl() ) {
					wp_style_add_data( $args['handle'], 'path', $rtl_file_path );
				}
			}
		}

		// Enqueue the stylesheet.
		wp_enqueue_style( $args['handle'] );

		return $content;
	};

	$hook = did_action( 'wp_enqueue_scripts' ) ? 'wp_footer' : 'wp_enqueue_scripts';
	if ( wp_should_load_block_assets_on_demand() ) {
		/**
		 * Callback function to register and enqueue styles.
		 *
		 * @param string $content The block content.
		 * @param array  $block   The full block, including name and attributes.
		 * @return string Block content.
		 */
		$callback_separate = static function ( $content, $block ) use ( $block_name, $callback ) {
			if ( ! empty( $block['blockName'] ) && $block_name === $block['blockName'] ) {
				return $callback( $content );
			}
			return $content;
		};

		/*
		 * The filter's callback here is an anonymous function because
		 * using a named function in this case is not possible.
		 *
		 * The function cannot be unhooked, however, users are still able
		 * to dequeue the stylesheets registered/enqueued by the callback
		 * which is why in this case, using an anonymous function
		 * was deemed acceptable.
		 */
		add_filter( 'render_block', $callback_separate, 10, 2 );
		return;
	}

	/*
	 * The filter's callback here is an anonymous function because
	 * using a named function in this case is not possible.
	 *
	 * The function cannot be unhooked, however, users are still able
	 * to dequeue the stylesheets registered/enqueued by the callback
	 * which is why in this case, using an anonymous function
	 * was deemed acceptable.
	 */
	add_filter( $hook, $callback );

	// Enqueue assets in the editor.
	add_action( 'enqueue_block_assets', $callback );
}

/**
 * Loads classic theme styles when the current theme lacks a theme.json file.
 *
 * This is used for backwards compatibility for Button and File blocks specifically.
 *
 * @since 6.1.0
 * @since 6.2.0 Added File block styles.
 * @since 6.8.0 Moved stylesheet registration outside of this function.
 */
function wp_enqueue_classic_theme_styles() {
	if ( ! wp_theme_has_theme_json() ) {
		wp_enqueue_style( 'classic-theme-styles' );
	}
}

/**
 * Enqueues the assets required for the Command Palette.
 *
 * @since 6.9.0
 *
 * @global array  $menu
 * @global array  $submenu
 */
function wp_enqueue_command_palette_assets() {
	global $menu, $submenu;

	$command_palette_settings = array(
		'is_network_admin' => is_network_admin(),
	);

	/**
	 * Extracts root-level text nodes from HTML string.
	 *
	 * @ignore
	 * @param string $label HTML string to extract text from.
	 * @return string Extracted text content, trimmed.
	 */
	$extract_root_text = static function ( string $label ): string {
		if ( '' === $label ) {
			return '';
		}

		$processor  = new WP_HTML_Tag_Processor( $label );
		$text_parts = array();
		$depth      = 0;

		while ( $processor->next_token() ) {
			$token_type = $processor->get_token_type();

			if ( '#text' === $token_type ) {
				if ( 0 === $depth ) {
					$text_parts[] = $processor->get_modifiable_text();
				}
				continue;
			}

			if ( '#tag' !== $token_type ) {
				continue;
			}

			if ( $processor->is_tag_closer() ) {
				if ( $depth > 0 ) {
					--$depth;
				}
				continue;
			}

			$token_name = $processor->get_tag();
			if ( $token_name && ! WP_HTML_Processor::is_void( $token_name ) ) {
				++$depth;
			}
		}

		return trim( implode( '', $text_parts ) );
	};

	if ( $menu ) {
		$menu_commands = array();
		foreach ( $menu as $menu_item ) {
			if ( empty( $menu_item[0] ) || ! is_string( $menu_item[0] ) || ! empty( $menu_item[1] ) && ! current_user_can( $menu_item[1] ) ) {
				continue;
			}

			$menu_label = $extract_root_text( $menu_item[0] );
			$menu_url   = '';
			$menu_slug  = $menu_item[2];

			if ( preg_match( '/\.php($|\?)/', $menu_slug ) || wp_http_validate_url( $menu_slug ) ) {
				$menu_url = $menu_slug;
			} elseif ( ! empty( menu_page_url( $menu_slug, false ) ) ) {
				$menu_url = WP_HTML_Decoder::decode_attribute( menu_page_url( $menu_slug, false ) );
			}

			if ( $menu_url ) {
				$menu_commands[] = array(
					'label' => $menu_label,
					'url'   => $menu_url,
					'name'  => $menu_slug,
				);
			}

			if ( array_key_exists( $menu_slug, $submenu ) ) {
				foreach ( $submenu[ $menu_slug ] as $submenu_item ) {
					if ( empty( $submenu_item[0] ) || ! empty( $submenu_item[1] ) && ! current_user_can( $submenu_item[1] ) ) {
						continue;
					}

					$submenu_label = $extract_root_text( $submenu_item[0] );
					$submenu_url   = '';
					$submenu_slug  = $submenu_item[2];

					if ( preg_match( '/\.php($|\?)/', $submenu_slug ) || wp_http_validate_url( $submenu_slug ) ) {
						$submenu_url = $submenu_slug;
					} elseif ( ! empty( menu_page_url( $submenu_slug, false ) ) ) {
						$submenu_url = WP_HTML_Decoder::decode_attribute( menu_page_url( $submenu_slug, false ) );
					}
					if ( $submenu_url ) {
						$menu_commands[] = array(
							'label' => sprintf(
								/* translators: 1: Menu label, 2: Submenu label. */
								__( '%1$s > %2$s' ),
								$menu_label,
								$submenu_label
							),
							'url'   => $submenu_url,
							'name'  => $menu_slug . '-' . $submenu_item[2],
						);
					}
				}
			}
		}
		$command_palette_settings['menu_commands'] = $menu_commands;
	}

	wp_enqueue_script( 'wp-commands' );
	wp_enqueue_style( 'wp-commands' );
	wp_enqueue_script( 'wp-core-commands' );

	wp_add_inline_script(
		'wp-core-commands',
		sprintf(
			'wp.coreCommands.initializeCommandPalette( %s );',
			wp_json_encode( $command_palette_settings, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES )
		)
	);
}

/**
 * Removes leading and trailing _empty_ script tags.
 *
 * This is a helper meant to be used for literal script tag construction
 * within `wp_get_inline_script_tag()` or `wp_print_inline_script_tag()`.
 * It removes the literal values of "<script>" and "</script>" from
 * around an inline script after trimming whitespace. Typically this
 * is used in conjunction with output buffering, where `ob_get_clean()`
 * is passed as the `$contents` argument.
 *
 * Example:
 *
 *     // Strips exact literal empty SCRIPT tags.
 *     $js = '<script>sayHello();</script>;
 *     'sayHello();' === wp_remove_surrounding_empty_script_tags( $js );
 *
 *     // Otherwise if anything is different it warns in the JS console.
 *     $js = '<script type="module">console.log( "hi" );</script>';
 *     'console.error( ... )' === wp_remove_surrounding_empty_script_tags( $js );
 *
 * @since 6.4.0
 * @access private
 *
 * @see wp_print_inline_script_tag()
 * @see wp_get_inline_script_tag()
 *
 * @param string $contents Script body with manually created SCRIPT tag literals.
 * @return string Script body without surrounding script tag literals, or
 *                original contents if both exact literals aren't present.
 */
function wp_remove_surrounding_empty_script_tags( $contents ) {
	$contents = trim( $contents );
	$opener   = '<SCRIPT>';
	$closer   = '</SCRIPT>';

	if (
		strlen( $contents ) > strlen( $opener ) + strlen( $closer ) &&
		strtoupper( substr( $contents, 0, strlen( $opener ) ) ) === $opener &&
		strtoupper( substr( $contents, -strlen( $closer ) ) ) === $closer
	) {
		return substr( $contents, strlen( $opener ), -strlen( $closer ) );
	} else {
		$error_message = __( 'Expected string to start with script tag (without attributes) and end with script tag, with optional whitespace.' );
		_doing_it_wrong( __FUNCTION__, $error_message, '6.4' );
		return sprintf(
			'console.error(%s)',
			wp_json_encode(
				sprintf(
					/* translators: %s: wp_remove_surrounding_empty_script_tags() */
					__( 'Function %s used incorrectly in PHP.' ),
					'wp_remove_surrounding_empty_script_tags()'
				) . ' ' . $error_message
			)
		);
	}
}

/**
 * Adds hooks to load block styles on demand in classic themes.
 *
 * This function must be called before {@see wp_default_styles()} and {@see register_core_block_style_handles()} so that
 * the filters are added to cause {@see wp_should_load_separate_core_block_assets()} to return true.
 *
 * @since 6.9.0
 * @since 7.0.0 This is now invoked at the `wp_default_styles` action with priority 0 instead of at `init` with priority 8.
 *
 * @see _add_default_theme_supports()
 */
function wp_load_classic_theme_block_styles_on_demand(): void {
	// This is not relevant to block themes, as they are opted in to loading separate styles on demand via _add_default_theme_supports().
	if ( wp_is_block_theme() ) {
		return;
	}

	/*
	 * Make sure that wp_should_output_buffer_template_for_enhancement() returns true even if there aren't any
	 * `wp_template_enhancement_output_buffer` filters added, but do so at priority zero so that applications which
	 * wish to stream responses can more easily turn this off.
	 */
	add_filter( 'wp_should_output_buffer_template_for_enhancement', '__return_true', 0 );

	// If a site has opted out of the template enhancement output buffer, then bail.
	if ( ! wp_should_output_buffer_template_for_enhancement() ) {
		return;
	}

	// The following two filters are added by default for block themes in _add_default_theme_supports().

	/*
	 * Load separate block styles so that the large block-library stylesheet is not enqueued unconditionally, and so
	 * that block-specific styles will only be enqueued when they are used on the page. A priority of zero allows for
	 * this to be easily overridden by themes which wish to opt out. If a site has explicitly opted out of loading
	 * separate block styles, then abort.
	 */
	add_filter( 'should_load_separate_core_block_assets', '__return_true', 0 );
	if ( ! wp_should_load_separate_core_block_assets() ) {
		return;
	}

	/*
	 * Also ensure that block assets are loaded on demand (although the default value is from should_load_separate_core_block_assets).
	 * As above, a priority of zero allows for this to be easily overridden by themes which wish to opt out. If a site
	 * has explicitly opted out of loading block styles on demand, then abort.
	 */
	add_filter( 'should_load_block_assets_on_demand', '__return_true', 0 );
	if ( ! wp_should_load_block_assets_on_demand() ) {
		return;
	}

	// Add hooks which require the presence of the output buffer. Ideally the above two filters could be added here, but they run too early.
	add_action( 'wp_template_enhancement_output_buffer_started', 'wp_hoist_late_printed_styles' );
}

/**
 * Adds the hooks needed for CSS output to be delayed until after the content of the page has been established.
 *
 * @since 6.9.0
 *
 * @see wp_load_classic_theme_block_styles_on_demand()
 * @see _wp_footer_scripts()
 */
function wp_hoist_late_printed_styles(): void {
	// Skip the embed template on-demand styles aren't relevant, and there is no wp_head action.
	if ( is_embed() ) {
		return;
	}

	/*
	 * Add a placeholder comment into the inline styles for wp-block-library, after which the late block styles
	 * can be hoisted from the footer to be printed in the header by means of a filter below on the template enhancement
	 * output buffer.
	 *
	 * Note that wp_maybe_inline_styles() prepends the inlined style to the extra 'after' array, which happens after
	 * this code runs. This ensures that the placeholder appears right after any inlined wp-block-library styles,
	 * which would be common.css.
	 */
	$placeholder = sprintf( '/*%s*/', uniqid( 'wp_block_styles_on_demand_placeholder:' ) );
	$dependency  = wp_styles()->query( 'wp-block-library', 'registered' );
	if ( $dependency ) {
		if ( ! isset( $dependency->extra['after'] ) ) {
			wp_add_inline_style( 'wp-block-library', $placeholder );
		} else {
			array_unshift( $dependency->extra['after'], $placeholder );
		}
	}

	/*
	 * Create a substitute for `print_late_styles()` which is aware of block styles. This substitute does not print
	 * the styles, but it captures what would be printed for block styles and non-block styles so that they can be
	 * later hoisted to the HEAD in the template enhancement output buffer. This will run at `wp_print_footer_scripts`
	 * before `print_footer_scripts()` is called.
	 */
	$printed_core_block_styles  = '';
	$printed_other_block_styles = '';
	$printed_global_styles      = '';
	$printed_late_styles        = '';

	$capture_late_styles = static function () use ( &$printed_core_block_styles, &$printed_other_block_styles, &$printed_global_styles, &$printed_late_styles ) {
		// Gather the styles related to on-demand block enqueues.
		$all_core_block_style_handles  = array();
		$all_other_block_style_handles = array();
		foreach ( WP_Block_Type_Registry::get_instance()->get_all_registered() as $block_type ) {
			if ( str_starts_with( $block_type->name, 'core/' ) ) {
				foreach ( $block_type->style_handles as $style_handle ) {
					$all_core_block_style_handles[] = $style_handle;
				}
			} else {
				foreach ( $block_type->style_handles as $style_handle ) {
					$all_other_block_style_handles[] = $style_handle;
				}
			}
		}

		/*
		 * First print all styles related to core blocks which should be inserted right after the wp-block-library stylesheet
		 * to preserve the CSS cascade. The logic in this `if` statement is derived from `wp_print_styles()`.
		 */
		$enqueued_core_block_styles = array_values( array_intersect( $all_core_block_style_handles, wp_styles()->queue ) );
		if ( count( $enqueued_core_block_styles ) > 0 ) {
			ob_start();
			wp_styles()->do_items( $enqueued_core_block_styles );
			$printed_core_block_styles = (string) ob_get_clean();
		}

		// Capture non-core block styles so they can get printed at the point where wp_enqueue_registered_block_scripts_and_styles() runs.
		$enqueued_other_block_styles = array_values( array_intersect( $all_other_block_style_handles, wp_styles()->queue ) );
		if ( count( $enqueued_other_block_styles ) > 0 ) {
			ob_start();
			wp_styles()->do_items( $enqueued_other_block_styles );
			$printed_other_block_styles = (string) ob_get_clean();
		}

		// Capture the global-styles so that it can be printed at the point where wp_enqueue_global_styles() runs.
		if ( wp_style_is( 'global-styles' ) ) {
			ob_start();
			wp_styles()->do_items( array( 'global-styles' ) );
			$printed_global_styles = (string) ob_get_clean();
		}

		/*
		 * Print all remaining styles not related to blocks. This contains a subset of the logic from
		 * `print_late_styles()`, without admin-specific logic and the `print_late_styles` filter to control whether
		 * late styles are printed (since they are being hoisted anyway).
		 */
		ob_start();
		wp_styles()->do_footer_items();
		$printed_late_styles = (string) ob_get_clean();
	};

	/*
	 * If `_wp_footer_scripts()` was unhooked from the `wp_print_footer_scripts` action, or if `wp_print_footer_scripts()`
	 * was unhooked from running at the `wp_footer` action, then only add a callback to `wp_footer` which will capture the
	 * late-printed styles.
	 *
	 * Otherwise, in the normal case where `_wp_footer_scripts()` will run at the `wp_print_footer_scripts` action, then
	 * swap out `_wp_footer_scripts()` with an alternative which captures the printed styles (for hoisting to HEAD) before
	 * proceeding with printing the footer scripts.
	 */
	$wp_print_footer_scripts_priority = has_action( 'wp_print_footer_scripts', '_wp_footer_scripts' );
	if ( false === $wp_print_footer_scripts_priority || false === has_action( 'wp_footer', 'wp_print_footer_scripts' ) ) {
		// The normal priority for wp_print_footer_scripts() is to run at 20.
		add_action( 'wp_footer', $capture_late_styles, 20 );
	} else {
		remove_action( 'wp_print_footer_scripts', '_wp_footer_scripts', $wp_print_footer_scripts_priority );
		add_action(
			'wp_print_footer_scripts',
			static function () use ( $capture_late_styles ) {
				$capture_late_styles();
				print_footer_scripts();
			},
			$wp_print_footer_scripts_priority
		);
	}

	// Replace placeholder with the captured late styles.
	add_filter(
		'wp_template_enhancement_output_buffer',
		static function ( $buffer ) use ( $placeholder, &$printed_core_block_styles, &$printed_other_block_styles, &$printed_global_styles, &$printed_late_styles ) {

			// Anonymous subclass of WP_HTML_Tag_Processor which exposes underlying bookmark spans.
			$processor = new class( $buffer ) extends WP_HTML_Tag_Processor {
				/**
				 * Gets the span for the current token.
				 *
				 * @return WP_HTML_Span Current token span.
				 */
				private function get_span(): WP_HTML_Span {
					// Note: This call will never fail according to the usage of this class, given it is always called after ::next_tag() is true.
					$this->set_bookmark( 'here' );
					return $this->bookmarks['here'];
				}

				/**
				 * Inserts text before the current token.
				 *
				 * @param string $text Text to insert.
				 */
				public function insert_before( string $text ): void {
					$this->lexical_updates[] = new WP_HTML_Text_Replacement( $this->get_span()->start, 0, $text );
				}

				/**
				 * Inserts text after the current token.
				 *
				 * @param string $text Text to insert.
				 */
				public function insert_after( string $text ): void {
					$span = $this->get_span();

					$this->lexical_updates[] = new WP_HTML_Text_Replacement( $span->start + $span->length, 0, $text );
				}

				/**
				 * Removes the current token.
				 */
				public function remove(): void {
					$span = $this->get_span();

					$this->lexical_updates[] = new WP_HTML_Text_Replacement( $span->start, $span->length, '' );
				}

				/**
				 * Replaces the current token.
				 *
				 * @param string $text Text to replace with.
				 */
				public function replace( string $text ): void {
					$span = $this->get_span();

					$this->lexical_updates[] = new WP_HTML_Text_Replacement( $span->start, $span->length, $text );
				}
			};

			// Locate the insertion points in the HEAD.
			while ( $processor->next_tag( array( 'tag_closers' => 'visit' ) ) ) {
				if (
					'STYLE' === $processor->get_tag() &&
					'wp-global-styles-placeholder-inline-css' === $processor->get_attribute( 'id' )
				) {
					/** This is added in {@see wp_enqueue_global_styles()} */
					$processor->set_bookmark( 'wp_global_styles_placeholder' );
				} elseif (
					'STYLE' === $processor->get_tag() &&
					'wp-block-styles-placeholder-inline-css' === $processor->get_attribute( 'id' )
				) {
					/** This is added in {@see wp_enqueue_registered_block_scripts_and_styles()} */
					$processor->set_bookmark( 'wp_block_styles_placeholder' );
				} elseif (
					'STYLE' === $processor->get_tag() &&
					'wp-block-library-inline-css' === $processor->get_attribute( 'id' )
				) {
					/** This is added here in {@see wp_hoist_late_printed_styles()} */
					$processor->set_bookmark( 'wp_block_library' );
				} elseif ( 'HEAD' === $processor->get_tag() && $processor->is_tag_closer() ) {
					$processor->set_bookmark( 'head_end' );
					break;
				}
			}

			/**
			 * Replace the placeholder for global styles enqueued during {@see wp_enqueue_global_styles()}. This is done
			 * even if $printed_global_styles is empty.
			 */
			if ( $processor->has_bookmark( 'wp_global_styles_placeholder' ) ) {
				$processor->seek( 'wp_global_styles_placeholder' );
				$processor->replace( $printed_global_styles );
				$printed_global_styles = '';
			}

			/*
			 * Insert block styles right after wp-block-library (if it is present). The placeholder CSS comment will
			 * always be added to the wp-block-library inline style since it gets printed at `wp_head` before the blocks
			 * are rendered. This means that there may not actually be any block styles to hoist from the footer to
			 * insert after this inline style. The placeholder CSS comment needs to be added so that the inline style
			 * gets printed, but if the resulting inline style is empty after the placeholder is removed, then the
			 * inline style is removed.
			 */
			if ( $processor->has_bookmark( 'wp_block_library' ) ) {
				$processor->seek( 'wp_block_library' );

				$css_text = $processor->get_modifiable_text();

				/*
				 * Split the block library inline style by the placeholder to identify the original inlined CSS, which
				 * likely would be common.css, followed by any inline styles which had been added by the theme or
				 * plugins via `wp_add_inline_style( 'wp-block-library', '...' )`. The separate block styles loaded on
				 * demand will get inserted after the inlined common.css and before the extra inline styles added by the
				 * user.
				 */
				$css_text_around_placeholder = explode( $placeholder, $css_text, 2 );
				$extra_inline_styles         = '';
				if ( count( $css_text_around_placeholder ) === 2 ) {
					$css_text = $css_text_around_placeholder[0];
					if ( '' !== trim( $css_text ) ) {
						$inlined_src = wp_styles()->get_data( 'wp-block-library', 'inlined_src' );
						if ( $inlined_src ) {
							$css_text .= sprintf(
								"\n/*# sourceURL=%s */\n",
								esc_url_raw( $inlined_src )
							);
						}
					}
					$extra_inline_styles = $css_text_around_placeholder[1];
				}

				/*
				 * The placeholder CSS comment was added to the inline style in order to force an inline STYLE tag to
				 * be printed. Now that the inline style has been located and the placeholder comment has been removed, if
				 * there is no CSS left in the STYLE tag after removal, then remove the STYLE tag entirely.
				 */
				if ( '' === trim( $css_text ) ) {
					$processor->remove();
				} else {
					$processor->set_modifiable_text( $css_text );
				}

				$inserted_after            = $printed_core_block_styles;
				$printed_core_block_styles = '';

				/*
				 * Add a new inline style for any user styles added via wp_add_inline_style( 'wp-block-library', '...' ).
				 * This must be added here after $printed_core_block_styles to preserve the original CSS cascade when
				 * the combined block library stylesheet was used. The pattern here is checking to see if it is not just
				 * a sourceURL comment after the placeholder above is removed.
				 */
				if ( ! preg_match( ':^\s*(/\*# sourceURL=\S+? \*/\s*)?$:s', $extra_inline_styles ) ) {
					$style_processor = new WP_HTML_Tag_Processor( '<style></style>' );
					$style_processor->next_tag();
					$style_processor->set_attribute( 'id', 'wp-block-library-inline-css-extra' );
					$style_processor->set_modifiable_text( $extra_inline_styles );
					$inserted_after .= "{$style_processor->get_updated_html()}\n";
				}

				if ( '' !== $inserted_after ) {
					$processor->insert_after( "\n" . $inserted_after );
				}
			}

			// Insert block styles at the point where wp_enqueue_registered_block_scripts_and_styles() normally enqueues styles.
			if ( $processor->has_bookmark( 'wp_block_styles_placeholder' ) ) {
				$processor->seek( 'wp_block_styles_placeholder' );
				if ( '' !== $printed_other_block_styles ) {
					$processor->replace( "\n" . $printed_other_block_styles );
				} else {
					$processor->remove();
				}
				$printed_other_block_styles = '';
			}

			// Print all remaining styles.
			$remaining_styles = $printed_core_block_styles . $printed_other_block_styles . $printed_global_styles . $printed_late_styles;
			if ( $remaining_styles && $processor->has_bookmark( 'head_end' ) ) {
				$processor->seek( 'head_end' );
				$processor->insert_before( $remaining_styles . "\n" );
			}
			return $processor->get_updated_html();
		}
	);
}

/**
 * Return the corresponding JavaScript `dataset` name for an attribute
 * if it represents a custom data attribute, or `null` if not.
 *
 * Custom data attributes appear in an element's `dataset` property in a
 * browser, but there's a specific way the names are translated from HTML
 * into JavaScript. This function indicates how the name would appear in
 * JavaScript if a browser would recognize it as a custom data attribute.
 *
 * Example:
 *
 *     // Dash-letter pairs turn into capital letters.
 *     'postId'       === wp_js_dataset_name( 'data-post-id' );
 *     'Before'       === wp_js_dataset_name( 'data--before' );
 *     '-One--Two---' === wp_js_dataset_name( 'data---one---two---' );
 *
 *     // Not every attribute name will be interpreted as a custom data attribute.
 *     null === wp_js_dataset_name( 'post-id' );
 *     null === wp_js_dataset_name( 'data' );
 *
 *     // Some very surprising names will; for example, a property whose name is the empty string.
 *     '' === wp_js_dataset_name( 'data-' );
 *     0  === strlen( wp_js_dataset_name( 'data-' ) );
 *
 * @since 6.9.0
 *
 * @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
 * @see \wp_html_custom_data_attribute_name()
 *
 * @param string $html_attribute_name Raw attribute name as found in the source HTML.
 * @return string|null Transformed `dataset` name, if interpretable as a custom data attribute, else `null`.
 */
function wp_js_dataset_name( string $html_attribute_name ): ?string {
	if ( 0 !== substr_compare( $html_attribute_name, 'data-', 0, 5, true ) ) {
		return null;
	}

	$end = strlen( $html_attribute_name );

	/*
	 * If it contains characters which would end the attribute name parsing then
	 * something else is wrong and this contains more than just an attribute name.
	 */
	if ( ( $end - 5 ) !== strcspn( $html_attribute_name, "=/> \t\f\r\n", 5 ) ) {
		return null;
	}

	/**
	 * > For each name in list, for each U+002D HYPHEN-MINUS character (-)
	 * > in the name that is followed by an ASCII lower alpha, remove the
	 * > U+002D HYPHEN-MINUS character (-) and replace the character that
	 * > followed it by the same character converted to ASCII uppercase.
	 *
	 * @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
	 */
	$custom_name = '';
	$at          = 5;
	$was_at      = $at;

	while ( $at < $end ) {
		$next_dash_at = strpos( $html_attribute_name, '-', $at );
		if ( false === $next_dash_at || $next_dash_at === $end - 1 ) {
			break;
		}

		// Transform `-a` to `A`, for example.
		$c = $html_attribute_name[ $next_dash_at + 1 ];
		if ( ( $c >= 'A' && $c <= 'Z' ) || ( $c >= 'a' && $c <= 'z' ) ) {
			$prefix       = substr( $html_attribute_name, $was_at, $next_dash_at - $was_at );
			$custom_name .= strtolower( $prefix );
			$custom_name .= strtoupper( $c );
			$at           = $next_dash_at + 2;
			$was_at       = $at;
			continue;
		}

		$at = $next_dash_at + 1;
	}

	// If nothing has been added it means there are no dash-letter pairs; return the name as-is.
	return '' === $custom_name
		? strtolower( substr( $html_attribute_name, 5 ) )
		: ( $custom_name . strtolower( substr( $html_attribute_name, $was_at ) ) );
}

/**
 * Returns a corresponding HTML attribute name for the given name,
 * if that name were found in a JS element’s `dataset` property.
 *
 * Example:
 *
 *     'data-post-id'        === wp_html_custom_data_attribute_name( 'postId' );
 *     'data--before'        === wp_html_custom_data_attribute_name( 'Before' );
 *     'data---one---two---' === wp_html_custom_data_attribute_name( '-One--Two---' );
 *
 *     // Not every attribute name will be interpreted as a custom data attribute.
 *     null === wp_html_custom_data_attribute_name( '/not-an-attribute/' );
 *     null === wp_html_custom_data_attribute_name( 'no spaces' );
 *
 *     // Some very surprising names will; for example, a property whose name is the empty string.
 *     'data-' === wp_html_custom_data_attribute_name( '' );
 *
 * @since 6.9.0
 *
 * @see https://html.spec.whatwg.org/#concept-domstringmap-pairs
 * @see \wp_js_dataset_name()
 *
 * @param string $js_dataset_name Name of JS `dataset` property to transform.
 * @return string|null Corresponding name of an HTML custom data attribute for the given dataset name,
 *                     if possible to represent in HTML, otherwise `null`.
 */
function wp_html_custom_data_attribute_name( string $js_dataset_name ): ?string {
	$end = strlen( $js_dataset_name );
	if ( 0 === $end ) {
		return 'data-';
	}

	/*
	 * If it contains characters which would end the attribute name parsing then
	 * something it’s not possible to represent this in HTML.
	 */
	if ( strcspn( $js_dataset_name, "=/> \t\f\r\n" ) !== $end ) {
		return null;
	}

	$html_name = 'data-';
	$at        = 0;
	$was_at    = $at;

	while ( $at < $end ) {
		$next_upper_after = strcspn( $js_dataset_name, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', $at );
		$next_upper_at    = $at + $next_upper_after;
		if ( $next_upper_at >= $end ) {
			break;
		}

		$prefix     = substr( $js_dataset_name, $was_at, $next_upper_at - $was_at );
		$html_name .= strtolower( $prefix );
		$html_name .= '-' . strtolower( $js_dataset_name[ $next_upper_at ] );
		$at         = $next_upper_at + 1;
		$was_at     = $at;
	}

	if ( $was_at < $end ) {
		$html_name .= strtolower( substr( $js_dataset_name, $was_at ) );
	}

	return $html_name;
}