Why it matters
Paragraphs under ~1.4 line-height feel cramped and are harder to track, especially on long lines.
How to fix it
Use 1.5-1.65 for body text; reserve tight leading (1-1.2) for large headings.
Example
body { line-height: 1.55; }More design rules
void design reports 19 rules in this category. Measured design heuristics from computed styles: font families, type scale, line length, palette and accent sprawl, spacing grid, radius sprawl, dark mode and the tells of generated UI.
no-type-scaleToo many distinct font sizes (no type scale)line-length-longBody text lines are too longline-length-shortBody text lines are very short on desktopbody-text-smallBody text is smaller than 15px on mobileheading-trackingLarge headings use default letter-spacingheading-no-balanceHeadings do not use text-wrap: balancepalette-sprawlToo many distinct colorsmultiple-accentsMore than one accent hue