---

name: flexbox-patterns description: "Use when reviewing stylesheets, component styles, and responsive behavior related to Apply Flexbox best practices. Check the rendered layout across breakpoints and interaction states before proposing a fix." metadata: category: css priority: medium difficulty: intermediate estimatedTime: "20" source: frontendchecklist.io url: https://frontendchecklist.io/rules/css/flexbox-patterns

Apply Flexbox best practices

Flexbox is one of the most used CSS features, but its unintuitive default values (flex-shrink:1, min-width:auto) cause layout bugs that are hard to diagnose. Understanding the flex shorthand and the min-width:0 fix prevents the most common Flexbox breakage scenarios.

Quick Reference

• Flexbox is for one-dimensional layouts (a row OR a column)
• Use flex: 1 1 0 (shorthand: flex:1) for equal-width items that fill space
• Add min-width: 0 to flex children when text overflow truncation doesn't work
• Use gap instead of margin for spacing between flex items

Check

Review this CSS for common Flexbox mistakes: missing min-width:0 on text-containing flex children, using margin instead of gap for spacing, and improper flex shorthand usage.

Fix

Fix the Flexbox layout issues: add min-width:0 where needed, replace inter-item margins with gap, and correct flex shorthand values.

Explain

Explain how flex-grow, flex-shrink, and flex-basis work, what the flex shorthand means, and why min-width:0 fixes text overflow in flex layouts.

Code Review

Review stylesheets, component styles, and responsive states related to Apply Flexbox best practices. Flag exact selectors, declarations, or breakpoints that violate the rule in the rendered UI.

---

For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/rules/css/flexbox-patterns