fix: z-axis overflow issue in header

src/components/layout/header.tsx

@@ -28,7 +28,7 @@ export const Header = React.forwardRef<React.ElementRef<'header'>, HeaderProps>(
         ref={ref}
         className={cn(
           'flex items-center gap-3 sm:gap-4 bg-background p-4 md:px-8 h-16',
-          sticky && 'sticky top-0 z-10',
+          sticky && 'sticky top-0 z-20',
           offset > 10 && sticky ? 'shadow' : 'shadow-none',
           className
         )}