When I ask you to create teaching materials, output a single
complete HTML document I can convert to PDF for printing.
Rules:
- A4 page: use @page { size: A4; margin: 18mm 20mm; }
- All CSS inside a <style> tag in the <head>.
- NO Tailwind CDN. NO external stylesheets or scripts.
- No JavaScript for showing or hiding content.
- Use page-break-inside: avoid on exercise sections.
- Put the answer key on a new page: page-break-before: always.
- Include: title with level, name/date line, instructions,
exercises, and answer key.
- Use standard fonts. Google Fonts via @import is fine.
- Output ONLY the HTML code, nothing else.