--- title: position slug: Web/CSS/position translation_of: Web/CSS/position ---
position
, encontrada no CSS, define como um elemento pode ser posicionado (renderizado) no documento (página). Essa propriedade (position
) pode ser acompanhada de outras, tais como, {{Cssxref("top")}}, {{Cssxref("right")}}, {{Cssxref("bottom")}}, and {{Cssxref("left")}}, que determinam como ficará a localização final do objeto, permitindo seu deslocamento, como será apresentado adiante.relative
, absolute
, fixed
, or sticky
. ( Em outras palavras, são todos esses, com excessão do static
, sendo estático o valor como padrão do elemento.)position
como valor relative
. Com isso, a propriedade {{Cssxref("top")}} e {{Cssxref("bottom")}} determinam o deslocamento ou projeção vertical a posição padrão do elemento que estava definida por static
; Não sendo outro, o {{Cssxref("left")}} e o {{Cssxref("right")}}, por sua vez, determinam o deslocamento horizontal.position
o valor absolute
ou fixed
. Com {{Cssxref("top")}}, {{Cssxref("right")}}, {{Cssxref("bottom")}}, and {{Cssxref("left")}} é possível especificar o deslocamento das laterais (bordas) dos blocos que contém (containing block) os elementos. (O containing block, ou blocos que envolvem um elemento é definido como um antecessor relativo ao qual o elemento está posicionado, acomplado ou englobado. Se por ventura o elemento tiver definido margens (margin), ele são adicionados ao deslocamento (offset). O elemento estabelecerá um novo contexto de formatação do bloco (BFC) para seus conteúdos.position
como valor sticky
. Sendo tratado como um posicionamento relativo até que ultrapasse (atinja) os limites do bloco no qual está contido. (Se assemelha a configurar a propriedade {{Cssxref("top")}} com um valor diferente de automatático (auto)) Dentro do seu fluxo principal (fluxo raiz, ou o contêiner no qual ele desloca-se), No momento que há o deslocamento da página o elemento é tratado como "preso" ou "stuck" até encontrar-se com as paredes opostas do bloco no qual esteja contido.Maior parte do tempo, um elemento de posicionamento absoluto que tem {{Cssxref("height")}} e {{Cssxref("width")}} configurados como auto
são dimensionados de acordo com seu conteúdo interno. However, non-replaced, absolutely positioned elements can be made to fill the available vertical space by specifying both {{Cssxref("top")}} and {{Cssxref("bottom")}} and leaving {{Cssxref("height")}} unspecified (that is, auto
). They can likewise be made to fill the available horizontal space by specifying both {{Cssxref("left")}} and {{Cssxref("right")}} and leaving {{Cssxref("width")}} as auto
.
Exceto para esses casos descritos abaixo (para elementos de posicionamento absoluto que preenchem o espaço disponível):
top
e bottom
são definidos (tecnicamento não sendo auto
), top
prevalece.left
e right
são definidos, left
prevalece quando {{Cssxref("direction")}} é ltr
(Direção da escrita Portuguesa, Japonês na horizontal, etc.) e right
prevalece quando {{Cssxref("direction")}} for configurado rtl
( Padrão de escrita em idiomas como Persa, Arabe, Hebraico, etc.).A propriedade position
é definida com apenas uma palavra-chave da lista abaixo.
static
relative
top
, right
, bottom
, and left
. The offset does not affect the position of any other elements; thus, the space given for the element in the page layout is the same as if position were static
.z-index
is not auto
. Its effect on table-*-group
, table-row
, table-column
, table-cell
, and table-caption
elements is undefined.absolute
top
, right
, bottom
, and left
.z-index
is not auto
. The margins of absolutely positioned boxes do not collapse with other margins.fixed
transform
, perspective
, or filter
property set to something other than none
(see the CSS Transforms Spec), in which case that ancestor behaves as the containing block. (Note that there are browser inconsistencies with perspective
and filter
contributing to containing block formation.) Its final position is determined by the values of top
, right
, bottom
, and left
.sticky
top
, right
, bottom
, and left
. The offset does not affect the position of any other elements.overflow
is hidden
, scroll
, auto
, or overlay
), even if that ancestor isn't the nearest actually scrolling ancestor. This effectively inhibits any "sticky" behavior (see the Github issue on W3C CSSWG).Relatively positioned elements are offset a given amount from their normal position within the document, but without the offset affecting other elements. In the example below, note how the other elements are placed as if "Two" were taking up the space of its normal location.
<div class="box" id="one">One</div> <div class="box" id="two">Two</div> <div class="box" id="three">Three</div> <div class="box" id="four">Four</div>
.box { display: inline-block; width: 100px; height: 100px; background: red; color: white; } #two { position: relative; top: 20px; left: 20px; background: blue; }
{{ EmbedLiveSample('Relative_positioning', '600px', '200px') }}
Elements that are relatively positioned remain in the normal flow of the document. In contrast, an element that is absolutely positioned is taken out of the flow; thus, other elements are positioned as if it did not exist. The absolutely positioned element is positioned relative to its nearest positioned ancestor (i.e., the nearest ancestor that is not static
). If a positioned ancestor doesn't exist, it is positioned relative to the ICB (initial containing block — see also the W3C definition), which is the containing block of the document's root element.
A simple example follows:
<h1>Absolute positioning</h1> <p>I am a basic block level element. My adjacent block level elements sit on new lines below me.</p> <p class="positioned">By default we span 100% of the width of our parent element, and we are as tall as our child content. Our total width and height is our content + padding + border width/height.</p> <p>We are separated by our margins. Because of margin collapsing, we are separated by the width of one of our margins, not both.</p> <p>inline elements <span>like this one</span> and <span>this one</span> sit on the same line as one another, and adjacent text nodes, if there is space on the same line. Overflowing inline elements <span>wrap onto a new line if possible — like this one containing text</span>, or just go on to a new line if not, much like this image will do: <img src="https://mdn.mozillademos.org/files/13360/long.jpg"></p>
body { width: 500px; margin: 0 auto; } p { background: aqua; border: 3px solid blue; padding: 10px; margin: 10px; } span { background: red; border: 1px solid black; } .positioned { position: absolute; background: yellow; top: 30px; left: 30px; }
{{ EmbedLiveSample('Absolute_positioning', '100%', 420) }}
Fixed positioning is similar to absolute positioning, with the exception that the element's containing block is the initial containing block established by the viewport, unless any ancestor has transform
, perspective
, or filter
property set to something other than none
(see CSS Transforms Spec), which then causes that ancestor to take the place of the elements containing block. This can be used to create a "floating" element that stays in the same position regardless of scrolling. In the example below, box "One" is fixed at 80 pixels from the top of the page and 10 pixels from the left. Even after scrolling, it remains in the same place relative to the viewport.
<div class="outer"> <p> Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam congue tortor eget pulvinar lobortis. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Nam ac dolor augue. Pellentesque mi mi, laoreet et dolor sit amet, ultrices varius risus. Nam vitae iaculis elit. Aliquam mollis interdum libero. Sed sodales placerat egestas. Vestibulum ut arcu aliquam purus viverra dictum vel sit amet mi. Duis nisl mauris, aliquam sit amet luctus eget, dapibus in enim. Sed velit augue, pretium a sem aliquam, congue porttitor tortor. Sed tempor nisl a lorem consequat, id maximus erat aliquet. Sed sagittis porta libero sed condimentum. Aliquam finibus lectus nec ante congue rutrum. Curabitur quam quam, accumsan id ultrices ultrices, tempor et tellus. </p> <p> Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam congue tortor eget pulvinar lobortis. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Nam ac dolor augue. Pellentesque mi mi, laoreet et dolor sit amet, ultrices varius risus. Nam vitae iaculis elit. Aliquam mollis interdum libero. Sed sodales placerat egestas. Vestibulum ut arcu aliquam purus viverra dictum vel sit amet mi. Duis nisl mauris, aliquam sit amet luctus eget, dapibus in enim. Sed velit augue, pretium a sem aliquam, congue porttitor tortor. Sed tempor nisl a lorem consequat, id maximus erat aliquet. Sed sagittis porta libero sed condimentum. Aliquam finibus lectus nec ante congue rutrum. Curabitur quam quam, accumsan id ultrices ultrices, tempor et tellus. </p> <div class="box" id="one">One</div> </div>
.box { width: 100px; height: 100px; background: red; color: white; } #one { position: fixed; top: 80px; left: 10px; background: blue; } .outer { width: 500px; height: 300px; overflow: scroll; padding-left: 150px; }
{{ EmbedLiveSample('Fixed_positioning', '800px', '300px') }}
Sticky positioning can be thought of as a hybrid of relative and fixed positioning. A stickily positioned element is treated as relatively positioned until it crosses a specified threshold, at which point it is treated as fixed until it reaches the boundary of its parent. For instance...
#one { position: sticky; top: 10px; }
...would position the element with id one relatively until the viewport were scrolled such that the element would be less than 10 pixels from the top. Beyond that threshold, the element would be fixed to 10 pixels from the top.
A common use for sticky positioning is for the headings in an alphabetized list. The "B" heading will appear just below the items that begin with "A" until they are scrolled offscreen. Rather than sliding offscreen with the rest of the content, the "B" heading will then remain fixed to the top of the viewport until all the "B" items have scrolled offscreen, at which point it will be covered up by the "C" heading, and so on.
You must specify a threshold with at least one of top
, right
, bottom
, or left
for sticky positioning to behave as expected. Otherwise, it will be indistinguishable from relative positioning.
<dl> <div> <dt>A</dt> <dd>Andrew W.K.</dd> <dd>Apparat</dd> <dd>Arcade Fire</dd> <dd>At The Drive-In</dd> <dd>Aziz Ansari</dd> </div> <div> <dt>C</dt> <dd>Chromeo</dd> <dd>Common</dd> <dd>Converge</dd> <dd>Crystal Castles</dd> <dd>Cursive</dd> </div> <div> <dt>E</dt> <dd>Explosions In The Sky</dd> </div> <div> <dt>T</dt> <dd>Ted Leo & The Pharmacists</dd> <dd>T-Pain</dd> <dd>Thrice</dd> <dd>TV On The Radio</dd> <dd>Two Gallants</dd> </div> </dl>
* { box-sizing: border-box; } dl > div { background: #FFF; padding: 24px 0 0 0; } dt { background: #B8C1C8; border-bottom: 1px solid #989EA4; border-top: 1px solid #717D85; color: #FFF; font: bold 18px/21px Helvetica, Arial, sans-serif; margin: 0; padding: 2px 0 0 12px; position: -webkit-sticky; position: sticky; top: -1px; } dd { font: bold 20px/45px Helvetica, Arial, sans-serif; margin: 0; padding: 0 0 0 12px; white-space: nowrap; } dd + dd { border-top: 1px solid #CCC; }
{{ EmbedLiveSample('Sticky_positioning', '500px', '300px') }}
Ensure that elements positioned with an absolute
or fixed
value do not obscure other content when the page is zoomed to increase text size.
Scrolling elements containing fixed
or sticky
content can cause performance and accessibility issues. As a user scrolls, the browser must repaint the sticky or fixed content in a new location. Depending on the content needing to be repainted, the browser performance, and the device's processing speed, the browser may not be able to manage repaints at 60 fps, causing accessibility concerns for people with sensitivities and jank for everyone. One solution is to add {{cssxref("will-change", "will-change: transform")}} to the positioned elements to render the element in its own layer, improving repaint speed and therefore improving performance and accessibility.
Specification | Status | Comment |
---|---|---|
{{SpecName('CSS2.1', 'visuren.html#propdef-position', 'position')}} | {{Spec2('CSS2.1')}} | |
{{SpecName('CSS3 Positioning','#position-property','position')}} | {{Spec2('CSS3 Positioning')}} | Adds sticky property value. |
{{cssinfo}}
{{Compat("css.properties.position")}}