Fix RTL styling on WordPress Core components

src/components/default-error-fallback.tsx

@@ -89,12 +89,16 @@ const RightPanel = () => {
 };
 
 export default function DefaultErrorFallback() {
+	const { isRTL } = useI18n();
+	const isRtl = isRTL();
+
+	const href = isRtl
+		? './main_window/styles/wordpress-components-style-rtl.css'
+		: './main_window/styles/wordpress-components-style.css';
+
 	return (
-		<div dir={ 'ltr' }>
-			<DynamicStylesheet
-				id="wordpress-components-style"
-				href={ '../main_window/styles/wordpress-components-style.css' }
-			/>
+		<div dir={ isRtl ? 'rtl' : 'ltr' }>
+			<DynamicStylesheet id="wordpress-components-style-error-fallback" href={ href } />
 			<VStack
 				className={ cx(
 					'h-screen bg-chrome backdrop-blur-3xl pr-chrome app-drag-region',

src/components/dynamic-stylesheet.tsx

@@ -17,7 +17,14 @@ export const DynamicStylesheet = ( { id, href }: DynamicStylesheetProps ) => {
 			linkElement.id = id;
 			linkElement.rel = 'stylesheet';
 			linkElement.type = 'text/css';
-			document.head.appendChild( linkElement );
+			const firstStylesheet =
+				document.head.querySelector( 'link[rel="stylesheet"]' ) ||
+				document.head.querySelector( 'style' );
+			if ( firstStylesheet ) {
+				document.head.insertBefore( linkElement, firstStylesheet );
+			} else {
+				document.head.appendChild( linkElement );
+			}
 			wasCreatedByUsRef = true;
 		}
 		linkElementRef.current = linkElement;

src/components/root.tsx

@@ -8,6 +8,7 @@ import App from 'src/components/app';
 import AuthProvider from 'src/components/auth-provider';
 import CrashTester from 'src/components/crash-tester';
 import ErrorBoundary from 'src/components/error-boundary';
+import { WordPressStyles } from 'src/components/wordpress-styles';
 import { SyncSitesProvider } from 'src/hooks/sync-sites/sync-sites-context';
 import { ContentTabsProvider } from 'src/hooks/use-content-tabs';
 import { FeatureFlagsProvider } from 'src/hooks/use-feature-flags';
@@ -34,6 +35,7 @@ const Root = () => {
 			<CacheProvider value={ emotionCache }>
 				<ReduxProvider store={ store }>
 					<I18nProvider i18n={ defaultI18n }>
+						<WordPressStyles />
 						<AuthProvider>
 							<ContentTabsProvider>
 								<SiteDetailsProvider>

src/components/tests/dynamic-stylesheet.test.tsx

@@ -43,18 +43,18 @@ describe( 'DynamicStylesheet', () => {
 		);
 		render( <DynamicStylesheet id="second-style" href="/second.css" /> );
 
-		// Get initial order
+		// Get initial order (new elements are inserted before existing ones)
 		const allLinks = document.head.querySelectorAll( 'link[id]' );
 		const initialOrder = Array.from( allLinks ).map( ( link ) => link.id );
-		expect( initialOrder ).toEqual( [ 'first-style', 'second-style' ] );
+		expect( initialOrder ).toEqual( [ 'second-style', 'first-style' ] );
 
 		// Update href of the first element
 		rerender1( <DynamicStylesheet id="first-style" href="/first-updated.css" /> );
 
 		// Order should be preserved
 		const allLinksAfterUpdate = document.head.querySelectorAll( 'link[id]' );
 		const orderAfterUpdate = Array.from( allLinksAfterUpdate ).map( ( link ) => link.id );
-		expect( orderAfterUpdate ).toEqual( [ 'first-style', 'second-style' ] );
+		expect( orderAfterUpdate ).toEqual( [ 'second-style', 'first-style' ] );
 
 		// Verify the href was actually updated
 		const firstElement = document.getElementById( 'first-style' ) as HTMLLinkElement;

src/components/wordpress-styles.tsx

@@ -0,0 +1,25 @@
+import { useI18n } from '@wordpress/react-i18n';
+import { DynamicStylesheet } from 'src/components/dynamic-stylesheet';
+
+const WORDPRESS_STYLES_ID = 'wordpress-components-style';
+
+// @ts-expect-error - import.meta syntax is not supported by TypeScript's commonjs module setting,
+// but Vite handles this at build time and replaces it with the actual value
+const isDevelopment = import.meta.env.DEV;
+
+const WORDPRESS_STYLES_LTR = isDevelopment
+	? '/node_modules/@wordpress/components/build-style/style.css'
+	: './main_window/styles/wordpress-components-style.css';
+
+const WORDPRESS_STYLES_RTL = isDevelopment
+	? '/node_modules/@wordpress/components/build-style/style-rtl.css'
+	: './main_window/styles/wordpress-components-style-rtl.css';
+
+export const WordPressStyles = () => {
+	const { isRTL } = useI18n();
+	const isRtl = isRTL();
+
+	const href = isRtl ? WORDPRESS_STYLES_RTL : WORDPRESS_STYLES_LTR;
+
+	return <DynamicStylesheet id={ WORDPRESS_STYLES_ID } href={ href } />;
+};

src/index.css

@@ -1,6 +1,4 @@
-/* Import WordPress component styles - these are handled by Vite */
-@import '@wordpress/components/build-style/style.css';
-
+/* WordPress component styles are loaded dynamically via WordPressStyles component */
 @tailwind base;
 @tailwind components;
 @tailwind utilities;