🗑️ Remove unused Nova app.css file to streamline vendor assets

resources/css/app.css

@@ -1,15 +1,33 @@
-@import 'utility-patterns.css';
-@import 'flatpickr.css';
+@import './utility-patterns.css' layer(base);
+@import './flatpickr.css' layer(base);
 
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import 'tailwindcss';
+
+@config '../../tailwind.config.js';
+
+/*
+  The default border color has changed to `currentcolor` in Tailwind CSS v4,
+  so we've added these compatibility styles to make sure everything still
+  looks the same as it did with Tailwind CSS v3.
+
+  If we ever want to remove these styles, we need to add an explicit border
+  color utility to any element that depends on these defaults.
+*/
+@layer base {
+  *,
+  ::after,
+  ::before,
+  ::backdrop,
+  ::file-selector-button {
+    border-color: var(--color-gray-200, currentcolor);
+  }
+}
 
 /* See Alpine.js: https://github.com/alpinejs/alpine#x-cloak */
 [x-cloak=""] {
     display: none;
 }
 
-@media screen and (max-width: theme('screens.lg')) {
+@media screen and (max-width: --theme(--breakpoint-lg)) {
     [x-cloak="lg"] { display: none; }
 }