Container Query
A container query lets CSS adapt a component to its own container. It checks that container’s size or style instead of only the viewport.
Another example
A product card shows full details in a wide area. In a narrow sidebar, it shows a short summary.
Main parts
- 01Outer constraint
- 02Content and spacing model
- 03Computed size or reflow result
Use it when
Use container queries when one reusable component appears in layout areas of different sizes.
Do not use it when
Never add many query rules when the content can already lay itself out well.
Name used in code
@container 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 Container Query to make the visual experience clear and easy to use. User context: A product card shows full details in a wide area. In a narrow sidebar, it shows a short summary. Design concept to apply: Container Query. Why it fits: Use container queries when one reusable component appears in layout areas of different sizes. Do not use it when: Never add many query rules when the content can already lay itself out well. 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 Container Query. Definition: A container query lets CSS adapt a component to its own container. It checks that container’s size or style instead of only the viewport. 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.