update dockerfile, css build and alpine images

Dockerfile

@@ -1,21 +1,34 @@
-FROM python:3.11-slim
+# --- STAGE 1: CSS Builder ---
+FROM node:18-alpine AS css-builder
+WORKDIR /app
+COPY package*.json tailwind.config.js ./
+COPY ./static/src/input.css ./static/src/input.css
+COPY ./templates ./templates
+RUN npm install && npx tailwindcss -i ./static/src/input.css -o ./static/dist/css/output.css --minify
+# --- STAGE 2: Final App (Python) ---
     
-ENV PYTHONDONTWRITEBYTECODE 1
-ENV PYTHONUNBUFFERED 1
 
+# --- STAGE 2: Python Builder (Compile dependencies) ---
+FROM python:3.11-alpine AS py-builder
+WORKDIR /app
+COPY requirements.txt .
+# Install into a local folder to copy easily
+RUN pip install --prefix=/install --no-cache-dir -r requirements.txt
+
+# --- STAGE 3: Final Minimal Image ---
+FROM python:3.11-alpine
 WORKDIR /app
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+# Copy only the installed python packages from py-builder
-    build-essential \
+COPY --from=py-builder /install /usr/local
-    && rm -rf /var/lib/apt/lists/*
+# Copy only the compiled CSS from css-builder
-
+COPY --from=css-builder /app/static/dist/css/output.css ./static/dist/css/output.css
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
 
+# Copy application code
 COPY . .
 
-EXPOSE 5000
+# Clean up any unneeded source files to save space
-
+RUN rm -rf static/src tailwind.config.js package*.json requirements.txt
 # Initialize DB, then start Gunicorn
 CMD python -c "from app import app, db; app.app_context().push(); db.create_all()" && \
     gunicorn --bind 0.0.0.0:5000 app:app