margin-right

摘要

margin-right  属性 设置与元素相关联的盒子模型的右外边距。这个值可以为负值。

竖直排列相邻的两个盒子模型的外边距会重叠，称为 margin collapsing.

语法

/* <length> values */
margin-right: 20px;        /* An absolute length */
margin-right: 1em;         /* A length relative to the text size */
margin-right: 5%;          /* A margin relative to the nearest block container's width */
/* Keyword values */
margin-right: auto;
/* Global values */
margin-right: inherit;
margin-right: initial;
margin-right: unset;

值

<length>

一个固定宽度 <length>值: 可以是一个绝对宽度，e.g. in px, 也可以是一个相对宽度， e.g. in em, 或者相对视窗的大小，e.g. in vh.

<percentage>

以百分比为单位的margin值，计算时是相对于其最近的父级容器的宽度。

auto

auto关键词表示在当前布局模式下，浏览器根据接收的左边距自动计算出外边距。如果有几组margin-left和margin-right 设置为auto，那么最后计算的空间分布，会根据display，float，position属性，自动生成以下几种情况：

Value of display	Value of float	Value of position	Computed value of auto	Comment
inline, inline-block, inline-table	any	static or relative	0	Inline layout mode
block, inline, inline-block, block, table, inline-table, list-item, table-caption	any	static or relative	0, except if both margin-left and margin-right are set to auto. In this case, it is set to the value centering the element inside its parent.	Block layout mode
block, inline, inline-block, block, table, inline-table, list-item, table-caption	left or right	static or relative	0	Block layout mode (floating element)
any table-*, except table-caption	any	any	0	Internal table-* elements don't have margins, use border-spacing instead
any, except flex, inline-flex, or table-*	any	fixed or absolute	0, except if both margin-left and margin-right are set to auto. In this case, it is set to the value centering the border area inside the available width, if fixed.	Absolutely positioned layout mode
flex, inline-flex	any	any	0, except if there is any positive horizontal free space. In this case, it is evenly distributed to all horizontal auto margins.	Flexbox layout mode

形式语法

<length> | <percentage> | auto

实例

.content { margin-right: 5%; }
.sidebox { margin-right: 10px; }
.logo    { margin-right: -5px; }

说明

浏览器兼容性