reconfigure css to allow consumer styling

It's a little jank, but it works. The consumer absolutely MUST have a
file at `$lib/styles/tailwind.css` that contains all necessary tailwind
imports AND also imports the `src/lib/styles/base.css` file from sui.

WILL address this in another commit.

src/lib/styles/base.css

@@ -1,12 +1,3 @@
-/* packages/ui/src/styles/theme.css */
-@import 'tailwindcss';
-
-@plugin '@tailwindcss/forms';
-@plugin '@tailwindcss/container-queries';
-@plugin 'tailwindcss-animate';
-
-@custom-variant dark (&:where(.dark, .dark *));
-
 @theme {
 	/* Fonts - easily overrideable */
 	--font-*: initial;
@@ -93,13 +84,3 @@
 	--transition-property-colors: background-color, border-color, color, fill, stroke;
 	--transition-property-font-color: color;
 }
-
-@layer base {
-	*,
-	::after,
-	::before,
-	::backdrop,
-	::file-selector-button {
-		border-color: var(--color-sui-gray-200, currentcolor);
-	}
-}

src/lib/styles/tailwind.css

@@ -0,0 +1,18 @@
+/* packages/ui/src/styles/tailwind.css */
+@import 'tailwindcss';
+@import '$lib/styles/base.css';
+@plugin '@tailwindcss/forms';
+@plugin '@tailwindcss/container-queries';
+@plugin 'tailwindcss-animate';
+
+@custom-variant dark (&:where(.dark, .dark *));
+
+@layer base {
+	*,
+	::after,
+	::before,
+	::backdrop,
+	::file-selector-button {
+		border-color: var(--color-sui-gray-200, currentcolor);
+	}
+}