Body Text Never Touches the Viewport Edge
MUST: Never let a paragraph or list item land within 16px of the left or right viewport edge — give the wrapping container at least 16px (ideally 24–32px) of horizontal padding, or a `max-width` plus `mx-auto` once there is room for one.
Give body copy a gutter — never let paragraphs bleed flush against the left or right edge of the screen
Bad
Good
Why it matters
This is distinct from cramped padding: there the container exists and is too tight, here the container is missing entirely. The detector flags a <p> or <li> with more than 40 characters of text, wider than 50% of the viewport, whose left edge sits less than 16px from the viewport edge (or whose right edge is within 16px of the far side). Text that runs into the physical edge of the screen has no margin for the eye to return to on each line wrap, and on a phone it collides with the rounded corners and the palm holding the device.
The fix is at least 16px — ideally 24–32px — of horizontal padding on a wrapping container, or a max-width plus mx-auto once there is room for one.