outline-width

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。

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

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

Browser compatibility