Tracking Issue: The great Accessibility Project

This is an issue used to track the accessibility of this book. It should keep note of issues like Dyslexia and just general accessibility of the material.

- [x] Set larger line spacing
- [ ] Find a decent sans-serif math font
- [ ] Keep paragraphs short, avoid "walls of text"
- [ ] Break paragraphs with example images (which can work as "checkpoints" for the reader)
- [ ] Consider using a less "white" background, to reduce visual stress
- [ ] Avoid justified text (if spaces change in length, things may be harder to read)
- [ ] Consider a bigger font size (12 to 14pt)
- [ ] Consider avoiding red and blue (colorblindness)
- [ ] Consider migrating to OpenDyslexic or using a well-made sans-serif font (with letters that look well differentiated from each other)
- [x] Improve contrast in boxes and captions (Contrast ratio of at least 4.5:1 as per WAI-WCAG AA, better if 7:1 - WCAG AAA)
- [x] Contrast in code captions (PDF version) is insufficient: 2.9:1
- [x] Contrast in tip boxes is sufficient (6.2:1 in title, 18.9:1 in content)
- [x] Contrast in Pitfall boxes is sufficient (6.5:1 in title, 19.2:1 in content)
- [x] Contrast in Trivia boxes is problematic (2.5:1 in title, 20.4:1 in content)
- [x] Contrast in Note boxes is problematic (2.4:1 in title, 19.8:1 in content)
- [x] Contrast in Wizardry boxes is sufficient (7.9:1 in title, 19.1:1 in content)
- [ ] Pure txt version with enhanced math for Visually Impaired people (see https://gitlab.com/Penaz/2dgd_f0th/-/issues/8)

This is a tracking issue for accessibility improvements to a book. The work involves multiple tasks like font selection, contrast checking, and formatting changes. Start by reviewing the existing book's source format (likely Markdown or LaTeX) and the linked issue about a text version for visually impaired readers. Each checkbox is a separate subtask; 'done' means completing an item and updating the checklist.

由索引模型根据 Issue 内容生成。