Index: src/wp-content/themes/twentytwentythree/functions.php
===================================================================
--- src/wp-content/themes/twentytwentythree/functions.php	(nonexistent)
+++ src/wp-content/themes/twentytwentythree/functions.php	(working copy)
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Twenty Twenty-Three functions and definitions
+ *
+ * @link https://developer.wordpress.org/themes/basics/theme-functions/
+ *
+ * @package WordPress
+ * @subpackage Twenty_Twenty_Three
+ * @since Twenty Twenty-Three 1.2
+ */
+
+
+/**
+ * Modifies the theme JSON data.
+ *
+ * @since Twenty Twenty-Three 1.2 Reverse Quote block border in right-to-left languages.
+ *
+ * @param object $theme_json The original theme JSON data.
+ * @return object The modified theme JSON data.
+ */
+function twentytwentythree_modify_theme_json( $theme_json ) {
+	if ( is_rtl() ) {
+		$new_data = array(
+			'version' => 2,
+			'styles'  => array(
+				'blocks' => array(
+					'core/quote' => array(
+						'border' => array(
+							'left'  => array(
+								'width' => '0px'
+							),
+							'right' => array(
+								'color' => 'inherit',
+								'style' => 'solid',
+								'width' => '1px'
+							)
+						)
+					)
+				)
+			)
+		);
+
+		// Returns the modified theme JSON data.
+		return $theme_json->update_with( $new_data );
+	}
+
+	// Returns the original theme JSON data.
+	return $theme_json;
+}
+
+// Runs the filter after theme setup.
+function twentytwentythree_apply_theme_json_theme_filters() {
+	add_filter( 'wp_theme_json_data_theme', 'twentytwentythree_modify_theme_json' );
+}
+add_action( 'after_setup_theme', 'twentytwentythree_apply_theme_json_theme_filters' );
+

Property changes on: src/wp-content/themes/twentytwentythree/functions.php
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Index: src/wp-content/themes/twentytwentythree/theme.json
===================================================================
--- src/wp-content/themes/twentytwentythree/theme.json	(revision 56164)
+++ src/wp-content/themes/twentytwentythree/theme.json	(working copy)
@@ -539,7 +539,11 @@
 			},
 			"core/quote": {
 				"border": {
-					"width": "1px"
+					"left": {
+						"color": "inherit",
+						"style": "solid",
+						"width": "1px"
+					}
 				},
 				"elements": {
 					"cite": {