test(admin-ui): guard against hardcoded neutral rgba in admin css

tests/Feature/AdminCssShouldNotHardcodeNeutralRgbaValuesTest.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminCssShouldNotHardcodeNeutralRgbaValuesTest 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_neutral_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);
+
+        // 中性色（15,23,42）也应尽量通过 token/var() 管理，避免散落硬编码导致“质感”不可统一。
+        // 说明：允许出现在 var() fallback 内（例如 var(--adm-shadow-popover, 0 12px 30px rgba(...)))。
+        $this->assertStringNotContainsString('background:rgba(15, 23, 42', $components);
+        $this->assertStringNotContainsString('background:rgba(15, 23, 42', $base);
+
+        $this->assertStringNotContainsString('box-shadow:0 12px 30px rgba(15, 23, 42', $components);
+        $this->assertStringNotContainsString('box-shadow:0 12px 30px rgba(15, 23, 42', $base);
+    }
+}