chore: tailwind v4 migration

src/tailwind.css

@@ -1,6 +1,24 @@
-@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);
+	}
+}
 
 @layer base {
 	html,
@@ -13,4 +31,8 @@
 	pre {
 		white-space: pre-wrap;
 	}
+
+	button {
+		@apply cursor-pointer;
+	}
 }