Fix PDF: full-height sidebar + space-between layout fills A4 page

- Use height: 276mm (fixed) instead of min-height so sidebar fills page
- Add height: 100% + box-sizing: border-box on sidebar
- Add justify-content: space-between on .main to distribute sections
- Slightly larger fonts (10-12.5px) and spacing for readability

Makefile

@@ -1,10 +1,17 @@
 .PHONY: run install docker-build docker-run stop
 
-run: install
-	FLASK_ENV=development PORT=9234 python3 app.py
+VENV=.venv
+PYTHON=$(VENV)/bin/python3
+PIP=$(VENV)/bin/pip3
 
-install:
-	pip3 install -r requirements.txt --quiet
+$(VENV)/bin/activate:
+	python3 -m venv $(VENV)
+
+install: $(VENV)/bin/activate
+	$(PIP) install -r requirements.txt --quiet
+
+run: install
+	FLASK_ENV=development PORT=9234 $(PYTHON) app.py
 
 docker-build:
 	docker build -t web-erika .