The bottom
CSS property participates in setting the vertical position of a positioned element. It has no effect on non-positioned elements.
The bottom
CSS property participates in setting the vertical position of a positioned element. It has no effect on non-positioned elements.
The effect of bottom
depends on how the element is positioned (i.e., the value of the position
property):
position
is set to absolute
or fixed
, the bottom
property specifies the distance between the element's outer margin of bottom edge and the inner border of the bottom edge of its containing block.position
is set to relative
, the bottom
property specifies the distance the element's bottom edge is moved above its normal position.position
is set to sticky
, the bottom
property is used to compute the sticky-constraint rectangle.position
is set to static
, the bottom
property has no effect.When both top
and bottom
are specified, position
is set to absolute
or fixed
, and height
is unspecified (either auto
or 100%
) both the top
and bottom
distances are respected. In all other situations, if height
is constrained in any way or position
is set to relative
, the top
property takes precedence and the bottom
property is ignored.
/* <length> values */ bottom: 3px; bottom: 2.4em; /* <percentage>s of the height of the containing block */ bottom: 10%; /* Keyword value */ bottom: auto; /* Global values */ bottom: inherit; bottom: initial; bottom: revert; bottom: revert-layer; bottom: unset;
<length>
A negative, null, or positive <length>
that represents:
<percentage>
A <percentage>
of the containing block's height.
auto
Specifies that:
top
property, while height: auto
is treated as a height based on the content; or if top
is also auto
, the element is positioned where it should vertically be positioned if it were a static element.top
property; or if top
is also auto
, the element is not moved vertically at all.inherit
Specifies that the value is the same as the computed value from its parent element (which might not be its containing block). This computed value is then handled as if it were a <length>
, <percentage>
, or the auto
keyword.
Initial value | auto |
---|---|
Applies to | positioned elements |
Inherited | no |
Percentages | refer to the height of the containing block |
Computed value | if specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
|
Animation type | a length, percentage or calc(); |
bottom =
auto |
<length-percentage>
<length-percentage> =
<length> |
<percentage>
This example demonstrates the difference in behavior of the bottom
property, when position
is absolute
versus fixed
.
<p> This<br />is<br />some<br />tall,<br />tall,<br />tall,<br />tall,<br />tall<br />content. </p> <div class="fixed"><p>Fixed</p></div> <div class="absolute"><p>Absolute</p></div>
p { font-size: 30px; line-height: 2em; } div { width: 48%; text-align: center; background: rgba(55, 55, 55, 0.2); border: 1px solid blue; } .absolute { position: absolute; bottom: 0; left: 0; } .fixed { position: fixed; bottom: 0; right: 0; }
Specification |
---|
CSS Positioned Layout Module Level 3 # insets |
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
bottom |
1 | 12 | 1 | 5In Internet Explorer versions before 7, when bothtop and bottom are specified, the element position is overconstrained and the top property has precedence; the computed value of bottom is set to -top , while its specified value is ignored. |
6 | 1 | ≤37 | 18 | 4 | 14 | 1 | 1.0 |
inset
, the shorthand for all related properties: top
, bottom
, left
, and right
inset-block-start
, inset-block-end
, inset-inline-start
, and inset-inline-end
and the shorthands inset-block
and inset-inline
position
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https://developer.mozilla.org/en-US/docs/Web/CSS/bottom