diff --git a/internal/tailwind-config/src/theme.css b/internal/tailwind-config/src/theme.css
index 2bf31bbe6..091a3efe1 100644
--- a/internal/tailwind-config/src/theme.css
+++ b/internal/tailwind-config/src/theme.css
@@ -1,11 +1,14 @@
 /*
  * 级联层顺序声明（必须先于 @import 'tailwindcss' 首次出现）：
- * preflight(base) < UI 库组件样式(antd / el / td) < Tailwind 工具类，
+ * properties(Tailwind 的 --tw-* 回退变量层) < preflight(base) <
+ * UI 库组件样式(antd / el / td) < Tailwind 工具类，
  * 使组件库样式（antdv-next 经 StyleProvider layer 注入 @layer antd；
  * element-plus / tdesign 经各自应用的 vite css-layer 插件包入对应层）
- * 能被工具类覆盖
+ * 能被工具类覆盖。
+ * 与 internal/vite-config/src/plugins/css-layer.ts 中的 LAYER_ORDER_STATEMENT
+ * 保持一致。
  */
-@layer theme, base, ant, antd, el, td, components, utilities;
+@layer properties, theme, base, ant, antd, el, td, components, utilities;
 
 @import 'tailwindcss';
 @import 'tw-animate-css';
diff --git a/internal/vite-config/src/plugins/css-layer.test.ts b/internal/vite-config/src/plugins/css-layer.test.ts
new file mode 100644
index 000000000..c2399a270
--- /dev/null
+++ b/internal/vite-config/src/plugins/css-layer.test.ts
@@ -0,0 +1,159 @@
+import { describe, expect, it } from 'vitest';
+
+import { viteCssLayerPlugin } from './css-layer';
+
+interface FakeAsset {
+  fileName: string;
+  source: string;
+  type: string;
+}
+
+function createBundle(assets: FakeAsset[]) {
+  return Object.fromEntries(assets.map((asset) => [asset.fileName, asset]));
+}
+
+const LAYER_ORDER_STATEMENT =
+  '@layer properties, theme, base, ant, antd, el, td, components, utilities;';
+
+describe('viteCssLayerPlugin', () => {
+  it('wraps matching css modules in the target layer', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const transform = plugin.transform;
+
+    if (typeof transform !== 'function') return;
+
+    const result = transform.call(
+      undefined as never,
+      '.el-button { color: red; }',
+      '/node_modules/element-plus/es/components/button/style/css/index.css?used',
+    );
+
+    expect(result).toEqual({
+      code: '@layer el {\n.el-button { color: red; }\n}',
+      map: null,
+    });
+  });
+
+  it('does not wrap css modules outside the target package', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const transform = plugin.transform;
+
+    if (typeof transform !== 'function') return;
+
+    const result = transform.call(
+      undefined as never,
+      '.local { color: red; }',
+      '/src/views/home/index.css',
+    );
+
+    expect(result).toBeUndefined();
+  });
+
+  it('injects the layer order statement into matching css assets', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const generateBundle = plugin.generateBundle;
+
+    if (typeof generateBundle !== 'function') return;
+
+    const bundle = createBundle([
+      {
+        fileName: 'element-x.css',
+        source: '@layer el{.el-button{color:red}}',
+        type: 'asset',
+      },
+      {
+        fileName: 'theme-x.css',
+        source: '.local { color: blue; }',
+        type: 'asset',
+      },
+    ]);
+
+    generateBundle.call(undefined as never, {} as never, bundle);
+
+    expect(bundle['element-x.css'].source).toBe(
+      `${LAYER_ORDER_STATEMENT}\n@layer el{.el-button{color:red}}`,
+    );
+    expect(bundle['theme-x.css'].source).toBe('.local { color: blue; }');
+  });
+
+  it('does not inject the statement twice when already present', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const generateBundle = plugin.generateBundle;
+
+    if (typeof generateBundle !== 'function') return;
+
+    const bundle = createBundle([
+      {
+        fileName: 'element-x.css',
+        source: `${LAYER_ORDER_STATEMENT}\n@layer el{.el-button{color:red}}`,
+        type: 'asset',
+      },
+    ]);
+
+    generateBundle.call(undefined as never, {} as never, bundle);
+
+    expect(bundle['element-x.css'].source).toBe(
+      `${LAYER_ORDER_STATEMENT}\n@layer el{.el-button{color:red}}`,
+    );
+  });
+
+  it('injects the statement even when the asset starts with a BOM', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const generateBundle = plugin.generateBundle;
+
+    if (typeof generateBundle !== 'function') return;
+
+    const bundle = createBundle([
+      {
+        fileName: 'element-x.css',
+        source: `\uFEFF@layer el{.el-button{color:red}}`,
+        type: 'asset',
+      },
+    ]);
+
+    generateBundle.call(undefined as never, {} as never, bundle);
+
+    expect(bundle['element-x.css'].source).toBe(
+      `${LAYER_ORDER_STATEMENT}\n\uFEFF@layer el{.el-button{color:red}}`,
+    );
+  });
+
+  it('ignores non-css assets', () => {
+    const plugin = viteCssLayerPlugin({
+      layerName: 'el',
+      packageName: 'element-plus',
+    });
+    const generateBundle = plugin.generateBundle;
+
+    if (typeof generateBundle !== 'function') return;
+
+    const bundle = createBundle([
+      {
+        fileName: 'element-x.js',
+        source: '@layer el{.el-button{color:red}}',
+        type: 'chunk',
+      },
+    ]);
+
+    generateBundle.call(undefined as never, {} as never, bundle);
+
+    expect(bundle['element-x.js'].source).toBe(
+      '@layer el{.el-button{color:red}}',
+    );
+  });
+});
diff --git a/internal/vite-config/src/plugins/css-layer.ts b/internal/vite-config/src/plugins/css-layer.ts
index d12e60cb8..9542bf2b3 100644
--- a/internal/vite-config/src/plugins/css-layer.ts
+++ b/internal/vite-config/src/plugins/css-layer.ts
@@ -11,12 +11,33 @@ function escapeRegExp(value: string): string {
   return value.replaceAll(/[.*+?^${}()|[\]\\]/g, String.raw`\$&`);
 }
 
+/**
+ * 与 internal/tailwind-config/src/theme.css 中的层顺序保持一致：
+ * properties(Tailwind 的 --tw-* 回退变量层) < preflight(base) <
+ * UI 库组件样式(antd / el / td) < Tailwind 工具类。
+ * 该声明必须在打包后注入：生产构建下 css 按 chunk 注入，若组件库的 css
+ * chunk 先于含层顺序声明的 theme.css 加载，层名会先被注册为最低优先级，
+ * 导致 Tailwind base/utilities 覆盖组件样式。打包后在每个含组件库层的
+ * css 产物顶部补上该声明，无论 chunk 加载顺序如何，层优先级都正确
+ * （theme.css 先加载时该声明是幂等的 no-op）。
+ * 注意 properties 必须排在首位：它是 Tailwind 为不支持 @property 的旧
+ * 浏览器准备的 --tw-* 回退变量层，必须始终是最低优先级，否则其回退声明
+ * 会覆盖工具类写入的变量。
+ */
+const LAYER_ORDER_STATEMENT =
+  '@layer properties, theme, base, ant, antd, el, td, components, utilities;';
+
 /**
  * 把指定包内的 css 包进 @layer：
  * 组件库的 css 是无层样式，无层样式在级联中永远压过 @layer 内的 Tailwind 工具类；
  * 包层后由 theme.css 的层声明决定顺序（utilities 排在组件库层之后），
  * 使 Tailwind 工具类可以覆盖组件库样式。
  *
+ * 注意：层顺序声明不能在 transform 阶段随包层 css 一起输出——rolldown-vite
+ * 的 css 合并会将「层顺序声明 + @layer 规则」形式的模块拆层（规则被脱层），
+ * 且产物压缩阶段也会丢弃该声明。因此改在 generateBundle 阶段对最终 css
+ * 产物统一注入（见 LAYER_ORDER_STATEMENT）。
+ *
  * @example
  * ```ts
  * plugins: [viteCssLayerPlugin({ packageName: 'element-plus', layerName: 'el' })]
@@ -41,5 +62,28 @@ export function viteCssLayerPlugin(
         return { code: `@layer ${matched.layerName} {\n${code}\n}`, map: null };
       }
     },
+    generateBundle(_options, bundle) {
+      for (const file of Object.values(bundle)) {
+        if (file.type !== 'asset' || !file.fileName.endsWith('.css')) {
+          continue;
+        }
+        const css = file.source.toString();
+        const matched = matchers.some((m) =>
+          css.includes(`@layer ${m.layerName}`),
+        );
+        if (!matched) {
+          continue;
+        }
+        // 先去除可能的 BOM 再判断，避免重复注入层顺序声明
+        const hasStatement = css
+          .replace(/^\uFEFF/, '')
+          .trimStart()
+          .startsWith(LAYER_ORDER_STATEMENT);
+        if (hasStatement) {
+          continue;
+        }
+        file.source = `${LAYER_ORDER_STATEMENT}\n${css}`;
+      }
+    },
   };
 }