/, where Markdown is not escaped.
	 * @return string
	 */
	protected function children_md( $node, $in_code = false ) {
		$out = '';
		foreach ( $node->childNodes as $child ) {
			$out .= $this->node_to_md( $child, $in_code );
		}

		return $out;
	}

	/**
	 * @param \DOMNode $node
	 * @param bool     $in_code
	 * @return string
	 */
	protected function node_to_md( $node, $in_code = false ) {
		if ( XML_TEXT_NODE === $node->nodeType ) {
			$text = preg_replace( '/\s+/', ' ', $node->nodeValue );

			return $in_code ? $text : $this->escape( $text );
		}
		if ( XML_ELEMENT_NODE !== $node->nodeType ) {
			return '';
		}

		$tag = strtolower( $node->nodeName );

		// BetterDocs code snippets carry their own toolbar and line-number column;
		// the toolbar is already pruned, so emit just the code with its language.
		if ( 'div' === $tag && $this->node_has_class( $node, 'betterdocs-code-snippet-wrapper' ) ) {
			return $this->fence( $node->textContent, $node->getAttribute( 'data-language' ) );
		}

		$inner = $this->children_md( $node, $in_code );

		switch ( $tag ) {
			case 'h1':
			case 'h2':
			case 'h3':
			case 'h4':
			case 'h5':
			case 'h6':
				return "\n\n" . str_repeat( '#', (int) substr( $tag, 1 ) ) . ' ' . trim( $inner ) . "\n\n";

			case 'p':
				return "\n\n" . trim( $inner ) . "\n\n";

			case 'br':
				return "  \n";

			case 'hr':
				return "\n\n---\n\n";

			case 'strong':
			case 'b':
				return '' === trim( $inner ) ? '' : '**' . trim( $inner ) . '**';

			case 'em':
			case 'i':
				return '' === trim( $inner ) ? '' : '*' . trim( $inner ) . '*';

			case 'del':
			case 's':
			case 'strike':
				return '' === trim( $inner ) ? '' : '~~' . trim( $inner ) . '~~';

			case 'mark':
				return trim( $inner );

			case 'kbd':
			case 'samp':
				return '`' . trim( $node->textContent ) . '`';

			case 'sup':
				return '^' . trim( $inner );

			case 'sub':
				return '~' . trim( $inner );

			case 'a':
				$href = $node->getAttribute( 'href' );
				$text = trim( $inner );
				if ( '' === $href ) {
					return $text;
				}

				return '[' . ( '' === $text ? $href : $text ) . '](' . $href . ')';

			case 'img':
				$src = $node->getAttribute( 'src' );

				return '' === $src ? '' : '![' . $this->escape( $node->getAttribute( 'alt' ) ) . '](' . $src . ')';

			case 'figure':
				return "\n\n" . trim( $inner ) . "\n\n";

			case 'figcaption':
				return '' === trim( $inner ) ? '' : "\n" . trim( $inner ) . "\n";

			case 'iframe':
				$src = $node->getAttribute( 'src' );
				if ( '' === $src ) {
					return '';
				}
				$label = $node->getAttribute( 'title' );

				return "\n\n[" . ( '' === $label ? $src : $this->escape( $label ) ) . '](' . $src . ")\n\n";

			case 'code':
				// Inline code only; fenced blocks are handled by 
.
				return '`' . trim( $node->textContent ) . '`';

			case 'pre':
				return $this->fence( $node->textContent, $this->language_of( $node ) );

			case 'blockquote':
				$quote = trim( $this->children_md( $node, $in_code ) );

				return "\n\n" . preg_replace( '/^/m', '> ', $quote ) . "\n\n";

			case 'ul':
				return "\n\n" . $this->list_md( $node, false ) . "\n\n";

			case 'ol':
				return "\n\n" . $this->list_md( $node, true ) . "\n\n";

			case 'table':
				return $this->table_md( $node );

			case 'dl':
				return "\n\n" . trim( $inner ) . "\n\n";

			case 'dt':
				return "\n" . '**' . trim( $inner ) . '**' . "\n";

			case 'dd':
				return ': ' . trim( $inner ) . "\n";

			default:
				return $inner; // unwrap unknown containers (div/span/section/…)
		}
	}

	/**
	 * Escape the Markdown metacharacters that would otherwise reformat prose.
	 *
	 * Intra-word underscores are deliberately left alone: CommonMark does not treat
	 * them as emphasis, so escaping them only makes identifiers like `my_var` uglier
	 * for the model reading them.
	 *
	 * @param string $text
	 * @return string
	 */
	protected function escape( $text ) {
		return preg_replace( '/([\\\\`\*\[\]])/', '\\\\$1', (string) $text );
	}

	/**
	 * @param \DOMNode $node
	 * @param string   $class
	 * @return bool
	 */
	protected function node_has_class( $node, $class ) {
		if ( ! $node instanceof \DOMElement ) {
			return false;
		}

		return in_array( $class, preg_split( '/\s+/', trim( $node->getAttribute( 'class' ) ) ), true );
	}

	/**
	 * Language hint for a fenced block, read from the usual `language-*` class on
	 * the 
 or its child .
	 *
	 * @param \DOMNode $node
	 * @return string
	 */
	protected function language_of( $node ) {
		$candidates = [ $node ];

		foreach ( $node->childNodes as $child ) {
			if ( XML_ELEMENT_NODE === $child->nodeType && 'code' === strtolower( $child->nodeName ) ) {
				$candidates[] = $child;
			}
		}

		foreach ( $candidates as $candidate ) {
			if ( ! $candidate instanceof \DOMElement ) {
				continue;
			}
			if ( preg_match( '/(?:language|lang|brush:)[-\s]([a-z0-9#+_-]+)/i', $candidate->getAttribute( 'class' ), $m ) ) {
				return strtolower( $m[1] );
			}
		}

		return '';
	}

	/**
	 * @param string $code
	 * @param string $language
	 * @return string
	 */
	protected function fence( $code, $language = '' ) {
		$code = rtrim( ltrim( (string) $code, "\r\n" ) );

		if ( '' === trim( $code ) ) {
			return '';
		}

		// Use a longer fence when the snippet itself contains a triple backtick.
		$fence = preg_match( '/^\s*```/m', $code ) ? '````' : '```';

		return "\n\n" . $fence . $language . "\n" . $code . "\n" . $fence . "\n\n";
	}

	/**
	 * @param \DOMNode $node    The 
/
 element.
	 * @param bool     $ordered
	 * @return string
	 */
	protected function list_md( $node, $ordered ) {
		$lines = [];
		$index = 1;

		foreach ( $node->childNodes as $li ) {
			if ( XML_ELEMENT_NODE !== $li->nodeType || 'li' !== strtolower( $li->nodeName ) ) {
				continue;
			}

			$marker  = $ordered ? ( $index++ . '. ' ) : '- ';
			$content = trim( $this->children_md( $li ) );

			// Collapse blank lines inside the item so a nested list attaches directly
			// under its parent marker, then indent continuation lines to the marker
			// width (2 for "- ", 3 for "1. ").
			$content = preg_replace( "/\n{2,}/", "\n", $content );
			$content = str_replace( "\n", "\n" . str_repeat( ' ', strlen( $marker ) ), $content );

			$lines[] = $marker . $content;
		}

		return implode( "\n", $lines );
	}

	/**
	 * Convert a  to a GFM pipe table. Falls back to unwrapped text when the
	 * table has no rows we can line up.
	 *
	 * @param \DOMNode $node
	 * @return string
	 */
	protected function table_md( $node ) {
		$dom  = $node->ownerDocument;
		$rows = [];

		$tr_nodes = ( new \DOMXPath( $dom ) )->query( './/tr', $node );
		if ( ! $tr_nodes || 0 === $tr_nodes->length ) {
			return "\n\n" . trim( $this->children_md( $node ) ) . "\n\n";
		}

		foreach ( $tr_nodes as $tr ) {
			$cells = [];
			foreach ( $tr->childNodes as $cell ) {
				if ( XML_ELEMENT_NODE !== $cell->nodeType ) {
					continue;
				}
				$name = strtolower( $cell->nodeName );
				if ( 'td' !== $name && 'th' !== $name ) {
					continue;
				}
				// A pipe table cell is a single line; a literal pipe must be escaped.
				$text    = trim( preg_replace( "/\s*\n\s*/", ' ', $this->children_md( $cell ) ) );
				$cells[] = str_replace( '|', '\|', $text );
			}
			if ( $cells ) {
				$rows[] = $cells;
			}
		}

		if ( ! $rows ) {
			return '';
		}

		$columns = max( array_map( 'count', $rows ) );
		$header  = array_shift( $rows );
		$header  = array_pad( $header, $columns, '' );

		$out  = '| ' . implode( ' | ', $header ) . " |\n";
		$out .= '| ' . implode( ' | ', array_fill( 0, $columns, '---' ) ) . " |\n";

		foreach ( $rows as $row ) {
			$out .= '| ' . implode( ' | ', array_pad( $row, $columns, '' ) ) . " |\n";
		}

		return "\n\n" . rtrim( $out ) . "\n\n";
	}
}