Refactor site header, heroes, and design system

vitest.config.ts

@@ -0,0 +1,17 @@
+import path from "path";
+import { fileURLToPath } from "url";
+
+import { defineConfig } from "vitest/config";
+
+const rootDir = path.dirname(fileURLToPath(new URL(import.meta.url)));
+
+export default defineConfig({
+  resolve: {
+    alias: {
+      "@": rootDir,
+    },
+  },
+  test: {
+    environment: "node",
+  },
+});