block-size
Box and spacing
The size across the text flow; in horizontal writing it equals height.
| How to write it | block-size: auto; |
|---|---|
| Common values | auto, 100%, 200px |
| Inherited | No — it stops at this element |
| Category | Box and spacing |
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 block-size property?
The size across the text flow; in horizontal writing it equals height.
Q. How do you write block-size?
As block-size: auto; Common values include auto, 100%, 200px.
Q. Is block-size inherited?
No. It applies only where you write it, so each element needs its own declaration.
Q. What group does block-size belong to?
The box and spacing group.