Why it matters
Lines under ~45 characters break rhythm and make paragraphs look ragged and tall.
How to fix it
Widen the text column or reduce the font size slightly; aim for 55-75ch.
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.
too-many-font-familiesToo many font familiesno-type-scaleToo many distinct font sizes (no type scale)line-length-longBody text lines are too longbody-text-smallBody text is smaller than 15px on mobilebody-line-height-tightBody line-height is too tightheading-trackingLarge headings use default letter-spacingheading-no-balanceHeadings do not use text-wrap: balancepalette-sprawlToo many distinct colors