Reflow Content at 320 CSS Pixels | BeforeMerge Rules | BeforeMerge

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Reflow Content at 320 CSS Pixels

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Reflow Content at 320 CSS Pixels

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Content must reflow to a 320px-wide viewport (400% zoom) without requiring two-dimensional scrolling. (WCAG 2.1 SC 1.4.10)

Why This Matters

Zoom and mobile users must scroll both directions to read, making content hard or impossible to use.

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Why this matters

At 400% zoom on a 1280px screen, the effective viewport is ~320px wide. Content should reflow into a single column rather than forcing horizontal scrolling.

Good: responsive layouts with no fixed-width wrappers; horizontal scroll only for data tables/maps. Bad: fixed width: 1000px containers that overflow at small widths.