diff --git a/tests/Feature/AdminCssShouldNotHardcodePrimaryRgbaValuesTest.php b/tests/Feature/AdminCssShouldNotHardcodePrimaryRgbaValuesTest.php
new file mode 100644
index 0000000..5e46cd6
--- /dev/null
+++ b/tests/Feature/AdminCssShouldNotHardcodePrimaryRgbaValuesTest.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminCssShouldNotHardcodePrimaryRgbaValuesTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_admin_css_should_not_hardcode_primary_rgba_values(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $components = file_get_contents(public_path('css/admin-components.css'));
+        $base = file_get_contents(public_path('css/admin-base.css'));
+
+        $this->assertIsString($components);
+        $this->assertIsString($base);
+
+        // 交互色必须走 --adm-primary-* token。
+        // 允许在 var() fallback 中出现 rgba（例如 var(--adm-primary-tint-08, rgba(...)))；
+        // 但不允许直接写成 background:rgba(...) 或 border-color:rgba(...)。
+        $this->assertStringNotContainsString('background:rgba(22, 119, 255', $components);
+        $this->assertStringNotContainsString('border-color:rgba(22, 119, 255', $components);
+        $this->assertStringNotContainsString('background:rgba(22, 119, 255', $base);
+        $this->assertStringNotContainsString('box-shadow:0 0 0 3px rgba(22, 119, 255', $base);
+    }
+}