feat: upgrade to tailwind@4

apps/remix/package.json

@@ -40,8 +40,8 @@
     "@react-router/serve": "^7.12.0",
     "@simplewebauthn/browser": "^13.2.2",
     "@simplewebauthn/server": "^13.2.2",
+    "@tailwindcss/postcss": "^4.3.1",
     "@tanstack/react-query": "5.90.10",
-    "autoprefixer": "^10.4.22",
     "colord": "^2.9.3",
     "content-disposition": "^1.0.1",
     "framer-motion": "^12.23.24",
@@ -70,7 +70,7 @@
     "remeda": "^2.32.0",
     "remix-themes": "^2.0.4",
     "satori": "^0.18.3",
-    "tailwindcss": "^3.4.18",
+    "tailwindcss": "^4.3.1",
     "ts-pattern": "^5.9.0",
     "ua-parser-js": "^1.0.41",
     "uqr": "^0.1.2"