margin-bottom - CSS: Cascading Style Sheets 编辑

The 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.

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

Syntax

/* <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;

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

Values

<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.

Formal definition

Formal syntax

<length> | <percentage> | auto

Examples

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;
}

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

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