Typography improvements

[github-actions]

Changes Needed

Body text:

• Increase font size: 16px → 18px minimum
• Increase line height: 1.5 → 1.7
• Max width: 65-75 characters per line

Headings:

• Clear hierarchy (h1 > h2 > h3)
• Adequate spacing above/below
• Font weight adjustments

Code blocks:

• Syntax highlighting
• Copy button
• Proper background contrast

Acceptance Criteria

• Improved readability
• Clear visual hierarchy
• Mobile optimized
• Code blocks styled

Estimated Time: 1.5 hours