No Fixed Widths Narrow
Fixed pixel widths that cause horizontal overflow or layout breakage on viewports narrower than 375px are forbidden — use fluid widths, max-width, or container queries instead.
$ prime install @community/rule-no-fixed-widths-narrow Projection
Always in _index.xml · the agent never has to ask for this.
NoFixedWidthsNarrow [rule] v1.0.0
Fixed pixel widths that cause horizontal overflow or layout breakage on viewports narrower than 375px are forbidden — use fluid widths, max-width, or container queries instead.
Loaded when retrieval picks the atom as adjacent / supporting.
NoFixedWidthsNarrow [rule] v1.0.0
Fixed pixel widths that cause horizontal overflow or layout breakage on viewports narrower than 375px are forbidden — use fluid widths, max-width, or container queries instead.
Severity
high
Forbidden
- width: 400px on any block-level element without a max-width: 100% fallback
- min-width: 600px on form inputs, modals, or cards
- Fixed table column widths that force horizontal scroll on mobile
Correct Patterns
- width: min(400px, 100%) — never overflows its container
- max-width: 400px; width: 100% — fluid until 400px
- container queries for component-level layout changes
Loaded when retrieval picks the atom as a focal / direct hit.
NoFixedWidthsNarrow [rule] v1.0.0
Fixed pixel widths that cause horizontal overflow or layout breakage on viewports narrower than 375px are forbidden — use fluid widths, max-width, or container queries instead.
Severity
high
Forbidden
- width: 400px on any block-level element without a max-width: 100% fallback
- min-width: 600px on form inputs, modals, or cards
- Fixed table column widths that force horizontal scroll on mobile
Correct Patterns
- width: min(400px, 100%) — never overflows its container
- max-width: 400px; width: 100% — fluid until 400px
- container queries for component-level layout changes
Severity
high
Forbidden
- width: 400px on any block-level element without a max-width: 100% fallback
- min-width: 600px on form inputs, modals, or cards
- Fixed table column widths that force horizontal scroll on mobile
Correct Patterns
- width: min(400px, 100%) — never overflows its container
- max-width: 400px; width: 100% — fluid until 400px
- container queries for component-level layout changes
Source
prime-system/examples/frontend-design/primes/compiled/@community/rule-no-fixed-widths-narrow/atom.yaml