background-size
Colour and background
Sizes the background image; cover fills without gaps, contain shows all of it.
| How to write it | background-size: auto; |
|---|---|
| Common values | auto, cover, contain, 100% 100% |
| Inherited | No — it stops at this element |
| Part of | background |
| Category | Colour and background |
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 background-size property?
Sizes the background image; cover fills without gaps, contain shows all of it.
Q. How do you write background-size?
As background-size: auto; Common values include auto, cover, contain, 100% 100%.
Q. Is background-size inherited?
No. It applies only where you write it, so each element needs its own declaration.
Q. Which shorthand sets background-size?
background can set it in one line.