Problem

Educators may want to print individual sections as handouts or PDFs for students. The current site renders poorly when printed — the sticky nav, indigo backgrounds, and screen-optimized layout don't translate to paper.

Suggested approach

Add a @media print block (inline in index.html's <style> tag or as a separate print.css) that:

• Hides the nav, footer, <Arrows> navigation, and <TryIt> blocks (or renders TryIt prompts as plain block quotes)
• Expands all accordions (override display: none on closed panels)
• Sets text to black on white, removes background colors
• Forces single-column layout at full width
• Shows the full URL next to each <Ref> link (using CSS a::after { content: " (" attr(href) ")"; })
• Adds a printed-at URL/date in the footer using @page margin content

Scope note

This is a CSS-only change with no React modifications needed. A @media print stylesheet in index.html or Vite's CSS pipeline would suffice.

Acceptance criteria

• Ctrl+P / Cmd+P on any section page renders a clean, readable single-column layout
• Accordion content is fully visible (not collapsed)
• External links show their full URL
• Nav and interactive chrome are hidden