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• Calculating a property's actual value
• 规范
• 另请参阅
• 相关话题

actual value of a CSS property is the used value of that property after any necessary approximations have been applied. For example, a 用户代理 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

用户代理 performs four steps to calculate a property's actual (final) value:

1. First, the specified value is determined based on the result of cascading , 继承 , or using the initial value .
2. Next, the computed value is calculated according to the specification (for example, a span with position: absolute will have its computed display changed to block ).
3. Then, layout is calculated, resulting in the used value .
4. Finally, the used value is transformed according to the limitations of the local environment, resulting in the actual value.

规范

规范	状态	注释
CSS Level 2 (Revision 1) The definition of 'actual value' in that specification.	推荐	初始定义。

另请参阅

• CSS 关键概念： CSS 句法 , at-rule , comments , specificity and 继承 , the box , layout modes and visual formatting models , and margin collapsing , 或 initial , computed , resolved , specified , used , and actual values. Definitions of value syntax , shorthand properties and replaced elements .

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• 最后修改： Jul 14, 2020

相关话题

1. CSS
2. CSS 参考
3. actual value