margin-top

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

* Some parts of this feature may have varying levels of support.

margin-top CSS 属性用于设置元素的顶部外边距外边距区域。正值使它离相邻元素更远,而负值使它更靠近相邻元素。

尝试一下

此属性对于可替换的内联元素没有效果,比如 <span><code>

语法

css
/* <length> 值 */
margin-top: 10px; /* 绝对长度 */
margin-top: 1em; /* 相对与文本的大小 */
margin-top: 5%; /* 相对于最近的块容器的宽度 */

/* 关键字值 */
margin-top: auto;

/* 全局关键字值 */
margin-top: inherit;
margin-top: initial;
margin-top: revert;
margin-top: revert-layer;
margin-top: unset;

margin-top 属性可以用关键字 auto<length><percentage> 来设置。其值可以是正值、负值或零。

<length>

设置固定边距大小。

<percentage>

相对于包含块的内联尺寸(对于竖排语言则是宽度,这由 writing-mode 定义)的百分比边距大小。

auto

浏览器选择一个合适的值来使用。参见 margin

形式语法

margin-top = 
<length-percentage> |
auto |
<anchor-size()>

<length-percentage> =
<length> |
<percentage>

<anchor-size()> =
anchor-size( [ <anchor-name> || <anchor-size> ]? , <length-percentage>? )

<anchor-name> =
<dashed-ident>

<anchor-size> =
width |
height |
block |
inline |
self-block |
self-inline

示例

将上边距设置为正值和负值

css
.content {
  margin-top: 5%;
}
.sidebox {
  margin-top: 10px;
}
.logo {
  margin-top: -5px;
}
#footer {
  margin-top: 1em;
}

规范

Specification
CSS Box Model Module Level 3
# margin-physical

浏览器兼容性

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
margin-top
anchor-size()
Experimental
auto

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
In development. Supported in a pre-release version.
In development. Supported in a pre-release version.
No support
No support
Experimental. Expect behavior to change in the future.
See implementation notes.

参见