Add Tailwind dependencies and upgrade Node

Dockerfile

@@ -1,5 +1,5 @@
 # Stage 1: Build React Frontend
-FROM node:18-alpine as builder
+FROM node:20-alpine as builder
 WORKDIR /app
 COPY frontend/ ./frontend/
 WORKDIR /app/frontend

frontend/package.json

@@ -18,6 +18,9 @@
     "@types/node": "^22.14.0",
     "@vitejs/plugin-react": "^5.0.0",
     "typescript": "~5.8.2",
-    "vite": "^6.2.0"
+    "vite": "^6.2.0",
+    "tailwindcss": "^3.4.1",
+    "postcss": "^8.4.35",
+    "autoprefixer": "^10.4.18"
   }
-}
+}