The actual value of a CSS property is the used value of that property after any necessary approximations have been applied. For example, a user agent that can only render borders with a whole-number pixel width may round the thickness of the border to the nearest integer.
Calculating a property's actual value
The user agent performs four steps to calculate a property's actual (final) value:
- First, the specified value is determined based on the result of cascading, inheritance, or using the initial value.
- Next, the computed value is calculated according to the specification (for example, a
position: absolutewill have its computed
- Then, layout is calculated, resulting in the used value.
- Finally, the used value is transformed according to the limitations of the local environment, resulting in the actual value.
|Cascading Style Sheets Level 2 Revision 2 (CSS 2.2) Specification |