Don't Justify Without Hyphenation
NEVER: Ship `text-align: justify` without `hyphens: auto` — stretched word-spacing carves rivers of white through the paragraph. Left-align body text; if a justified column is non-negotiable, set `hyphens: auto` plus a `lang` attribute so the browser has a dictionary.
Left-align body text, or enable hyphens: auto if the design demands a justified column
p { text-align: justify; hyphens: auto; } /* requires <html lang="en"> */Bad
Good
Why it matters
Browsers justify a line by stretching word-spacing until it reaches both margins. On a narrow measure there are only a few gaps to absorb the slack, so each one grows, and when wide gaps stack across consecutive lines they carve visible vertical channels through the paragraph. impeccable's detector flags exactly the combination text-align: justify where hyphens is not auto.
Left alignment sidesteps the problem entirely; hyphens: auto (plus a lang attribute so the browser knows the dictionary) is the escape hatch when a justified column is non-negotiable.
References