feat: upgrade Tailwind CSS to v4.1.11

- Upgrade Tailwind CSS from 3.x to 4.x for latest features and performance
- Install @tailwindcss/postcss plugin for Tailwind CSS 4.0 compatibility
- Update CSS configuration to use new @import and @config syntax
- Update PostCSS configuration to use new plugin format
- Build working correctly with new Tailwind CSS engine

package.json

@@ -20,12 +20,13 @@
     "tippy.js": "^6.3.7"
   },
   "devDependencies": {
+    "@tailwindcss/postcss": "^4.1.11",
     "@tauri-apps/cli": "^1.6.3",
     "@types/debug": "^4.1.12",
     "@types/node": "^24.0.7",
     "autoprefixer": "^10.4.21",
     "postcss": "^8.5.6",
-    "tailwindcss": "^3.4.17",
+    "tailwindcss": "^4.1.11",
     "typescript": "^4.9.5",
     "vite": "^6.3.5",
     "vite-plugin-solid": "^2.11.7"

postcss.config.js

@@ -1,6 +1,6 @@
 module.exports = {
   plugins: {
-    tailwindcss: {},
+    '@tailwindcss/postcss': {},
     autoprefixer: {},
   },
 }

src/styles.css

@@ -1,3 +1,3 @@
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import "tailwindcss";
+
+@config "../tailwind.config.js";