outline-width - CSS（层叠样式表） 编辑

CSS 属性 outline-width 用于设置一个元素的轮廓的厚度。元素轮廓是绘制于元素周围的一条线，位于 border 的外围。

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大多情况下用简写属性 outline 定义轮廓外观会更方便。

Syntax

/* Keyword values */
outline-width: thin;
outline-width: medium;
outline-width: thick;

/* <length> values */
outline-width: 1px;
outline-width: 0.1em;

/* Global values */
outline-width: inherit;

outline-width 的值可以是下面列表中的任一项。

Values

<length>

The width of the outline specified as a <length>.

thin

取决于用户代理。通常等同于桌面浏览器的 1px （包括 Firefox）。

medium

取决于用户代理。通常等同于桌面浏览器的 3px （包括 Firefox）。

thick

取决于用户代理。通常等同于桌面浏览器的 5px（包括 Firefox）。

Formal syntax

<line-width>
where 
<line-width> = <length> | thin | medium | thick

Examples

HTML

<span id="thin">thin</span>
<span id="medium">medium</span>
<span id="thick">thick</span>
<span id="twopixels">2px</span>
<span id="oneex">1ex</span>
<span id="em">1.2em</span>

CSS

span {
  outline-style: solid;
  display: inline-block;
  margin: 20px;
}

#thin {
  outline-width: thin;
}

#medium {
  outline-width: medium;
}

#thick {
  outline-width: thick;
}

#twopixels {
  outline-width: 2px;
}

#oneex {
  outline-width: 1ex;
}

#em {
  outline-width: 1.2em;
}

Specifications

Specification	Status	Comment
CSS Basic User Interface Module Level 3 outline-width	Recommendation	No change.
CSS Transitions outline-width	Working Draft	Defines outline-width as animatable.
CSS Level 2 (Revision 1) outline-width	Recommendation	Initial definition.

初始值	medium
适用元素	all elements
是否是继承属性	否
计算值	an absolute length; if the keyword none is specified, the computed value is 0
Animation type	a length

Browser compatibility

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The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.