Guide · Agent skill
How to use the Flexbox Layout Patterns agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The flexbox-patterns skill is an agent skill that makes an AI coding agent review your CSS for common Flexbox mistakes and propose fixes. It is aimed at front-end developers, developers maintaining older stylesheets, and designers or students who want a plain-language explanation of flex sizing. After this guide you will know what the skill does, how to install it, how to ask for it in natural language, and what to check before accepting its changes.
Flexbox Layout Patternsthedaviddias/Front-End-Checklist · MIT Download the skill Quick start
- 1Download the ZIP. Download the flexbox-patterns ZIP from this page and unzip it.
- 2Choose an install location. Place the folder in ~/.claude/skills/ for personal use or .claude/skills/ inside a project. In the Claude apps, upload it under Settings → Capabilities → Skills instead.
- 3Open your stylesheet. Open the project with the CSS or component styles you want reviewed.
- 4Ask a natural question. Describe the layout problem or ask for a Flexbox review of specific styles.
- 5Review the proposed fix. Read the changed selectors and declarations the agent suggests before applying them.
- 6Test across breakpoints. Check the rendered layout at the widths and states where the problem appears.
What is an agent skill and what does this one do?
An agent skill is a folder of instructions that an AI agent loads when a request matches the skill's description. This one comes from the Front-End Checklist project and is scoped to one rule: applying Flexbox best practices.
Flexbox is a one-dimensional layout system (a row or a column). Its default values, such as flex-shrink: 1 and min-width: auto, often cause items to overflow or refuse to shrink. The skill focuses on these problems.
- Checks CSS for missing min-width: 0 on text-containing flex children
- Flags using margin instead of gap for spacing between flex items
- Looks for incorrect flex shorthand usage
- Proposes fixes and explains how flex-grow, flex-shrink, flex-basis and min-width work
How do you install the flexbox-patterns skill?
Download the ZIP from this page and unzip it. You can install the skill in one of two places: your personal skills folder or a single project's skills folder.
For a personal install, place the unzipped skill folder in ~/.claude/skills/. For a project install, place it in the project's .claude/skills/ folder.
If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.
- Personal: ~/.claude/skills/
- Project only: .claude/skills/ inside your project
- Claude apps: Settings → Capabilities → Skills, then upload
Which files does the skill contain?
The skill has two files. SKILL.md holds the trigger description, the quick reference and the instructions for the Check, Fix, Explain and Code Review tasks. references/rule.md holds the fuller rule page with a code example of flex shorthand values and the reasoning behind them.
The skill's requirements are not listed. It does not run scripts and does not use the network.
- SKILL.md: trigger description and task instructions
- references/rule.md: full rule notes and flex shorthand examples
How do you trigger the skill with a natural request?
You do not need a special command. Ask the agent about stylesheets, component styles or responsive behaviour involving Flexbox, and the skill's description should match. Mention the symptom you see, since the skill is written around bugs such as overflow and items that will not shrink.
Asking for a check across breakpoints and interaction states fits the skill's description well, because it is written to look at the rendered layout before proposing a fix.
- "Review my navbar CSS for Flexbox mistakes."
- "My product title overflows its flex row. Why, and how do I fix it?"
- "Replace the margins between my flex items with gap and check the result on mobile."
- "Explain what flex: 1 1 0 does compared with flex: 1 1 auto."
What does a typical fix look like?
The most common fix is adding min-width: 0 to a flex child that holds text, so that text truncation works. Another is switching inter-item margins to gap. The rule's quick reference gives the shorthand forms you should expect the agent to use.
Always review the diff the agent proposes and test it in your browser at the breakpoints you care about.
- flex: 1 1 0 (shorthand flex: 1) for equal-width items that fill space
- flex: 0 0 auto or flex: none for fixed-size items
- flex: 0 1 auto is the browser default (shrink only)
flex: 1 1 0; /* Grow and shrink equally, start from 0 (shorthand: flex:1) */
flex: none; /* 0 0 auto — fixed size, no flex */What are the safety notes and limits?
The skill runs no scripts and uses no network access, so it only reads and edits the CSS you give it. Its scope is narrow: it covers one Flexbox rule, not general CSS, CSS Grid, absolute positioning, a full design system or an accessibility audit.
Use it for flex layouts. For grid-based or absolute-positioned layouts, ask for help from a different resource.
- Runs scripts: no
- Uses network: no
- Requires: nothing listed
- Not for CSS Grid, absolute-positioned layouts, design systems or accessibility audits
What tips help you get better results?
Give the agent the exact selector and the markup context, and say which breakpoint or state is broken. Ask it to explain its reasoning if you are learning how flex sizing works.
Keep changes small and check each one in the browser, especially text truncation and spacing after switching to gap.
- Paste the selector and the declarations, not just a description
- Name the breakpoint (for example mobile width) where the bug appears
- Ask for an explanation of flex-grow, flex-shrink and flex-basis alongside the fix
What people use it for
- Fixing text that overflows a flex row because the child lacks min-width: 0
- Replacing margin-based spacing between flex items with gap in an older stylesheet
- Correcting flex shorthand values so items fill space or stay fixed size
- Getting a plain-language explanation of flex-grow, flex-shrink, flex-basis and min-width
Frequently asked questions
How do I install the flexbox-patterns skill?
Download the ZIP from this page and unzip it. Place the folder in ~/.claude/skills/ for personal use or in a project's .claude/skills/ folder. In the Claude apps, you can upload it under Settings → Capabilities → Skills.
Does the flexbox-patterns skill have any requirements?
The source lists no requirements. It does not run scripts and does not use the network.
Is the flexbox-patterns skill free?
The skill is licensed under MIT. The source does not list pricing for it.
Can this skill fix CSS Grid layouts?
No. The skill is scoped to one-dimensional Flexbox, and its reference is not about CSS Grid. Use a different resource for grid or absolute-positioned layouts.
Why does my flex child text not truncate?
A common cause is missing min-width: 0 on the flex child that holds the text, because min-width defaults to auto. The skill checks for this and proposes adding min-width: 0 where needed.
What is the difference between flex: 1 and flex: none?
flex: 1 is shorthand for flex: 1 1 0, so items grow and shrink equally from zero. flex: none is 0 0 auto, meaning the item keeps its content size and does not flex.
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Our verdict
This skill suits front-end developers fixing text overflow or non-shrinking items in flex rows and columns, and developers replacing old margin spacing with gap. It is a poor choice if you need CSS Grid help, a full design system, or an accessibility audit, since it covers only this one Flexbox rule.
Download the skill