diff --git a/web/src/app/layout.tsx b/web/src/app/layout.tsx
index cc95153..232aaa7 100644
--- a/web/src/app/layout.tsx
+++ b/web/src/app/layout.tsx
@@ -29,6 +29,19 @@ export default function RootLayout({
 }: Readonly<{ children: React.ReactNode }>) {
   return (
     <html lang="en" className={`${geist.variable}`} suppressHydrationWarning>
+      <head>
+        {/* Define isSpace function globally to fix markdown-it issues with Next.js + Turbopack
+          https://github.com/markdown-it/markdown-it/issues/1082#issuecomment-2749656365 */}
+        <Script id="markdown-it-fix" strategy="beforeInteractive">
+          {`
+            if (typeof window !== 'undefined' && typeof window.isSpace === 'undefined') {
+              window.isSpace = function(code) {
+                return code === 0x20 || code === 0x09 || code === 0x0A || code === 0x0B || code === 0x0C || code === 0x0D;
+              };
+            }
+          `}
+        </Script>
+      </head>
       <body className="bg-app">
         <ThemeProviderWrapper>{children}</ThemeProviderWrapper>
         <Toaster />
