contain
Layout
Promises the element's effects stay inside it, so the browser can skip work.
| How to write it | contain: none; |
|---|---|
| Common values | none, strict, content, layout, paint, size |
| Inherited | No — it stops at this element |
| Category | Layout |
How to read this
- An inherited property only needs writing once on the parent — every child picks it up. Most text properties work this way.
- A shorthand resets whatever you leave out. Writing background: red alone also wipes a background image you set earlier.
- When rules collide, the more specific selector wins; only when specificity ties does source order decide.
- Animate transform and opacity for smoothness. Changing width or top forces the layout to be recalculated.
Frequently asked questions
Q. What is the CSS contain property?
Promises the element's effects stay inside it, so the browser can skip work.
Q. How do you write contain?
As contain: none; Common values include none, strict, content, layout.
Q. Is contain inherited?
No. It applies only where you write it, so each element needs its own declaration.
Q. What group does contain belong to?
The layout group.