chore(docs): bump to tailwind 4.0

This is [a new major version of Tailwind CSS][release-announcement],
which includes a lot of breaking changes. This commit updates the
project to use the new version.

[release-announcement]: https://blog.tailwindcss.com/tailwindcss-v4

docs/astro.config.mjs

@@ -1,6 +1,6 @@
 import { defineConfig } from 'astro/config';
 import starlight from '@astrojs/starlight';
-import tailwind from '@astrojs/tailwind';
+import tailwindcss from '@tailwindcss/vite';
 
 const isLocalPreview = process.env.npm_lifecycle_script === 'astro dev';
 
@@ -153,13 +153,11 @@ export default defineConfig({
             {
               label: 'Releasing a new version',
               link: '/internal/releasing',
-            }
-          ]
+            },
+          ],
         },
       ],
     }),
-    tailwind({
-      applyBaseStyles: false,
-    }),
+    tailwindcss(),
   ],
 });

docs/package.json

@@ -12,14 +12,15 @@
     "@astrojs/check": "^0.9.4",
     "@astrojs/starlight": "^0.31.1",
     "@astrojs/starlight-tailwind": "^3.0.0",
-    "@astrojs/tailwind": "^5.1.4",
     "@fontsource-variable/inter": "^5.1.1",
+    "@tailwindcss/vite": "^4.0.0",
     "astro": "^5.1.7",
     "sharp": "^0.33.5",
-    "tailwindcss": "^3.4.17",
+    "tailwindcss": "^4.0.0",
     "typescript": "^5.7.3"
   },
   "devDependencies": {
     "prettier": "^3.4.2"
-  }
+  },
+  "packageManager": "pnpm@9.15.4+sha512.b2dc20e2fc72b3e18848459b37359a32064663e5627a51e4c74b2c29dd8e8e0491483c3abb40789cfd578bf362fb6ba8261b05f0387d76792ed6e23ea3b1b6a0"
 }