Flexbox
Flexbox is a CSS layout system for one direction at a time. It lines up and spreads items across a row or a column.
Another example
A toolbar keeps its title on the left and its actions on the right. Every control stays centered from top to bottom.
Main parts
- 01Outer constraint
- 02Content and spacing model
- 03Computed size or reflow result
Use it when
Use Flexbox for a row or column needing alignment, wrapping, or content-based sizes.
Do not use it when
Use CSS Grid for clear two-way layouts. Never force Flexbox to manage rows and columns together.
Name used in code
display: flex Before you ship
Check content order, shared design values, component consistency, contrast, zoom, and layout changes by screen size. Verify every theme, language, and state. If there is motion, offer an equal reduced-motion experience.
Outcome: Use or define Flexbox to make the visual experience clear and easy to use. User context: A toolbar keeps its title on the left and its actions on the right. Every control stays centered from top to bottom. Design concept to apply: Flexbox. Why it fits: Use Flexbox for a row or column needing alignment, wrapping, or content-based sizes. Do not use it when: Use CSS Grid for clear two-way layouts. Never force Flexbox to manage rows and columns together. Design requirements: Set the content order, shared design values, and reusable components. Define how the layout changes by screen size and state. Keep useful design choices separate from decoration. Inclusion and resilience: Check contrast, zoom, languages, themes, and reduced motion when needed. Do not use color or effects as the only way to show meaning. Acceptance criteria: The design stays clear on phones and desktops, at zoom, in every theme, and in all supported languages. Interactive states stay clear and consistent. Evidence and limits (evidence boundary): A formal document may still be a draft, release candidate, or final version. Check its status and browser or platform support. Unknowns to confirm: Brand limits, amount of content, supported themes and languages, target devices, and design-system rules.
Check this request
Review the current use of Flexbox. Definition: Flexbox is a CSS layout system for one direction at a time. It lines up and spreads items across a row or a column. Release checks: Check content order, shared design values, component consistency, contrast, zoom, and layout changes by screen size. Verify every theme, language, and state. If there is motion, offer an equal reduced-motion experience. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.