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• 句法
• 形式定义
• 形式句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

margin-bottom CSS property sets the margin area on the bottom of an element. A positive value places it farther from its neighbors, while a negative value places it closer.

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.

This property has no effect on non- replaced inline elements, such as <span> or <code> .

句法

/* <length> values */
margin-bottom: 10px;  /* An absolute length */
margin-bottom: 1em;   /* relative to the text size */
margin-bottom: 5%;    /* relative to the nearest block container's width */
/* Keyword values */
margin-bottom: auto;
/* Global values */
margin-bottom: inherit;
margin-bottom: initial;
margin-bottom: unset;
					

margin-bottom property is specified as the keyword auto ，或 <length> ，或 <percentage> . Its value can be positive, zero, or negative.

值

<length>

The size of the margin as a fixed value.

<percentage>

The size of the margin as a percentage, relative to the width of the containing block.

auto

The browser selects a suitable value to use. See margin .

形式定义

初始值	0
适用于	all elements, except elements with table display types other than table-caption , table and inline-table . It also applies to ::first-letter and ::first-line .
继承	no
百分比	refer to the width of the containing block
计算值	the percentage as specified or the absolute length
动画类型	a length

形式句法

<length> | <percentage> | auto
					

范例

Setting positive and negative bottom margins

HTML

<div class="container">
<div class="box0">Box 0</div>
<div class="box1">Box 1</div>
<div class="box2">Box one's negative margin pulls me up</div>
</div>
					

CSS

CSS for divs to set margin-bottom and height

.box0 {
    margin-bottom:1em;
    height:3em;
}
.box1 {
    margin-bottom:-1.5em;
    height:4em;
}
.box2 {
    border:1px dashed black;
    border-width:1px 0;
    margin-bottom:2em;
}
					

Some definitions for container and divs so margins' effects can be seen more clearly

.container {
    background-color:orange;
    width:320px;
    border:1px solid black;
}
div {
    width:320px;
    background-color:gold;
}
					

结果

规范

规范	状态	注释
CSS 基本 Box 模型 The definition of 'margin-bottom' in that specification.	工作草案	No significant change
CSS Level 2 (Revision 1) The definition of 'margin-bottom' in that specification.	推荐	Removes its effect on inline elements.
CSS Level 1 The definition of 'margin-bottom' in that specification.	推荐	初始定义

浏览器兼容性

The compatibility table on 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. 更新 GitHub 上的兼容性数据

	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
margin-bottom	Chrome 完整支持 1	Edge 完整支持 12	Firefox 完整支持 1	IE 完整支持 3	Opera 完整支持 3.5	Safari 完整支持 1	WebView Android 完整支持 1	Chrome Android 完整支持 18	Firefox Android 完整支持 4	Opera Android 完整支持 10.1	Safari iOS 完整支持 1	Samsung Internet Android 完整支持 1.0
auto	Chrome 完整支持 1	Edge 完整支持 12 注意事项 完整支持 12 注意事项 注意事项 auto value is not supported in quirks mode.	Firefox 完整支持 1	IE 完整支持 6 注意事项 完整支持 6 注意事项 注意事项 auto value is not supported in quirks mode.	Opera 完整支持 3.5	Safari 完整支持 1	WebView Android 完整支持 37	Chrome Android 完整支持 18	Firefox Android 完整支持 4	Opera Android 完整支持 14	Safari iOS 完整支持 1	Samsung Internet Android 完整支持 1.0

图例

完整支持

完整支持

见实现注意事项。

见实现注意事项。

另请参阅

• margin-top , margin-right ，和 margin-left 和 margin 简写
• The mapped logical properties: margin-block-start , margin-block-end , margin-inline-start ，和 margin-inline-end and the shorthands margin-block and margin-inline

元数据

• 最后修改： Oct 5, 2020

相关话题

1. CSS
2. CSS 参考
3. CSS Box Model
4. 指南

   1. CSS 基本 Box 模型介绍
   2. Mastering margin collapsing
5. 特性

   1. height
   2. margin-bottom
   3. margin-left
   4. margin-right
   5. margin-top
   6. margin-trim
   7. max-height
   8. max-width
   9. min-height
   10. min-width
   11. overscroll-behavior
   12. overscroll-behavior-block
   13. overscroll-behavior-inline
   14. overscroll-behavior-x
   15. overscroll-behavior-y
   16. padding
   17. padding-bottom
   18. padding-left
   19. padding-right
   20. padding-top
   21. visibility
   22. width