diff --git a/src/components/site-header.tsx b/src/components/site-header.tsx
index 4958a37..5be4463 100644
--- a/src/components/site-header.tsx
+++ b/src/components/site-header.tsx
@@ -8,11 +8,11 @@ import { ThemeToggle } from "@/components/theme-toggle"
 
 export function SiteHeader() {
   return (
-    <header className="sticky top-0 z-999 w-full border-b bg-background">
+    <header className="sticky top-0 z-[999] w-full border-b bg-background">
       <div className="container flex h-20 items-center space-x-4 sm:justify-between sm:space-x-0">
         <MainNav items={siteConfig.mainNav} />
       </div>
     </header>
   )
 }
-  
\ No newline at end of file
+