dimension

<dimension> CSS 数据类型是一个带有单位的<number>，例如：10px

CSS使用度量值来描述距离 (<length>)，时间(<time>)，频率(<frequency>)，分辨率(<resolution>)以及其他量。

格式

<dimension> 的格式是一个<number>后紧随一个是标记符的单位，单位大小写不敏感。

12px      12像素
1rem      1 rem
1.2pt     1.2点
2200ms    2200毫秒
200hz     200赫兹
200Hz     200赫兹(单位大小写不敏感)

12 px       单位必须紧随数字，不能有空格
12"px"      单位是标识符，不能加引号

Specification	状态	说明
CSS Values and Units Module Level 4 <dimension>	Editor's Draft	添加 `cap`, `ic`, `lh`, `rlh`, `vi`, `vb`
CSS Values and Units Module Level 3 <dimension>	Candidate Recommendation	添加 `ch`, `rem`, `vw`, `vw`, `vmin`, `vmax`, `Q`
CSS Level 2 (Revision 1) <dimension>	Recommendation	Defined under Numbers and Length
CSS Level 1 <dimension>	Recommendation	Initial definition under "length units"

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
<dimension>	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 5	Opera Full support Yes	Safari Full support 1	WebView Android Full support ≤37	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support Yes	Safari iOS Full support 1	Samsung Internet Android Full support 1.0