Turn the PostgreSQL schema below into a finished visual ER diagram.
Return one complete HTML file in a single code block. I will save it as erd.html
and open it directly in my browser. No install, build step or internet connection.

Use readable table cards, inline CSS and inline SVG relationship connectors.
Give it a warm off-white background, dark text and muted green table headers.
Show every table and column with its exact name and SQL type, plus PK, FK and
unique markers. Explain composite keys without implying each column is unique.
Label each relationship with its foreign-key column and cardinality at both ends.
Derive cardinality from foreign keys, nullability and uniqueness. Include only
declared foreign keys; do not infer links from column names or redesign the schema.

Keep connectors outside the cards and make the whole diagram fit on a laptop screen.
On narrow screens, allow the whole diagram to scroll without disconnecting lines.
Include a text relationship list and a small legend beneath the diagram.
Keep all CSS and SVG inside the file. No JavaScript, external assets or libraries.
List any limitations after the code block.

