`Layer` prop on StyleProvider breaks styles after client-side navigation in Next.js App Router

[jaqubowsky]

Description

When using StyleProvider (or AntdRegistry from @ant-design/nextjs-registry) with the layer prop in a Next.js App Router application, styles work correctly on initial SSR load but break after client-side navigation.

Environment

• antd: 6.2.0
• @ant-design/cssinjs: 2.0.3
• @ant-design/nextjs-registry: 1.3.0
• next: 16.1.1
• react: 19.2.3
• tailwindcss: 4.1.18
• next-intl: "^4.7.0"

Steps to Reproduce

1. Set up Next.js App Router with Ant Design and Tailwind CSS v4
2. Configure StyleProvider with layer prop as per docs:

// app/layout.tsx
<StyleProvider cache={cache} hashPriority="high" layer>
  {children}
</StyleProvider>

3. Configure CSS layers for Tailwind v4 compatibility:

/* index.css */
@layer theme, base, antd, components, utilities;
@import "tailwindcss";

4. Load any page with Ant Design components (initial load works fine)
5. Navigate to another page using Next.js <Link> (client-side navigation)
6. Observe: Styles are broken/missing on the new page
7. Hard refresh the page
8. Observe: Styles work correctly again

Expected Behavior

Styles should persist and work correctly after client-side navigation, with dynamically injected styles properly wrapped in @layer antd { ... }.

Actual Behavior

After client-side navigation:

• Newly rendered Ant Design components have broken/missing styles
• Styles appear to either not be wrapped in @layer antd or have injection timing issues
• Hard refresh (full SSR) restores correct styling

Workaround

Remove the layer prop and use Tailwind's important modifier instead:

<StyleProvider cache={cache} hashPriority="high">
  {children}
</StyleProvider>

@layer theme, base, antd, components, utilities;
@import "tailwindcss" important;

Analysis

The layer prop works correctly during SSR (styles are extracted and wrapped in @layer antd). However, during client-side navigation, dynamically injected styles for new components appear to not respect the layer configuration, causing specificity conflicts with Tailwind utilities.