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margin-bottom

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.

The effect of the CSS margin-bottom property on the element box

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

Initial value 0
Applies to 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.
Inherited no
Percentages refer to the width of the containing block
Computed value the percentage as specified or the absolute length
Animation type a length

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

Specification Status Comment
CSS Basic Box Model
The definition of 'margin-bottom' in that specification.
Working Draft No significant change
CSS Level 2 (Revision 1)
The definition of 'margin-bottom' in that specification.
Recommendation Removes its effect on inline elements.
CSS Level 1
The definition of 'margin-bottom' in that specification.
Recommendation Initial definition

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
margin-bottom 1 12 1 3 3.5 1
auto 1 12
12
The auto value is not supported in quirks mode.
1 6
6
The auto value is not supported in quirks mode.
3.5 1
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
margin-bottom 1 18 4 10.1 1 1.0
auto 37 18 4 14 1 1.0

See also

© 2005–2020 Mozilla and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/CSS/margin-bottom