Typography hierarchy and readability optimization

Design optimal typography hierarchies for enhanced readability and user experience. Hierarchy levels: 1. H1 (biggest impact): 2-3x body text size, used once per page. 2. H2 (section headers): 1.5-2x body text. 3. H3 (subsections): 1.2-1.5x body text. 4. Body text: 16px minimum for web, 10-12pt for print. 5. Captions/footnotes: 80-90% of body text size. Readability factors: 1. Line height: 1.4-1.6x font size for optimal reading comfort. 2. Line length: 45-75 characters (including spaces) per line. 3. Contrast: minimum 4.5:1 ratio for normal text, 3:1 for large text. 4. Font pairing: maximum 2-3 typefaces, ensure stylistic harmony. Web considerations: system fonts for performance, font-display: swap for custom fonts. Print specifications: kerning adjustments, tracking for small sizes. Testing: readability tools, user testing with target demographics, eye-tracking studies for optimal scanning patterns.