fix: pin Tailwind config path + absolute content globs (cwd-independent PostCSS for CI)

tailwind.config.js

@@ -6,11 +6,18 @@
  * classes like `bg-primary` / `text-primary` automatically reflect the brand
  * without any template edits — change data/brand.yaml and rebuild.
  */
+const path = require("path");
+
 /** @type {import('tailwindcss').Config} */
 module.exports = {
+  // Resolve content globs absolute to THIS config file's directory so Tailwind
+  // scans the right files regardless of the process working directory. Hugo's
+  // PostCSS pipeline (css.PostCSS) does not always run with cwd = project root
+  // (notably in CI), and relative globs would then match nothing — producing
+  // empty CSS and "class does not exist" errors for @apply'd utilities.
   content: [
-    "./layouts/**/*.html",
-    "./content/**/*.{html,md}",
+    path.join(__dirname, "layouts/**/*.html"),
+    path.join(__dirname, "content/**/*.{html,md}"),
   ],
   theme: {
     extend: {