A propriedade

CSS

 background-position define a posição inicial, relativa a posição de fundo na camada definido por

background-origin

, para cada background image definido.

A fonte deste exemplo interativo está alocado em um repositório GitHub. Se você pudesse contribuir com os exemplos de projetos interativos , por favor “clone” 

https://github.com/mdn/interactive-examples

 e envie-nos um pull request.

/* Valores chave */ background-position: top; background-position: bottom; background-position: left; background-position: right; background-position: center; /* Valores <percentuais> */ background-position: 25% 75%; /* valores <espessura> */ background-position: 0 0; background-position: 1cm 2cm; background-position: 10ch 8em; /* Multiplas imagens */ background-position: 0 0, center; /* Valores de cantos relativos */ background-position: bottom 10px right 20px; background-position: right 3em bottom 10px; background-position: bottom 10px right; background-position: top right 10px; /* Valores globais */ background-position: inherit; background-position: initial; background-position: unset; 

A propriedade background-position é especificada como um determinado numero de valores de 

 , separados por espaços.

<position>

A

<position> (en-US)

. A position defines an x/y coordinate, to place an item relative to the edges of an element’s box. It can be defined using one or two values. If two values are used, the first value represents the horizontal position and the second represents the vertical position. If only one value is specified, the second value is assumed to be center.

1-value syntax: the value may be:

• The keyword value center, which centers the image.
• One of the keyword values top, left, bottom, right. This specifies an edge against which to place the item. The other dimension is then set to 50%, so the item is placed in the middle of the edge specified.
• A

  <length> (en-US)

  or

  <percentage> (en-US)

  . This specifies the X coordinate relative to the left edge, with the Y coordinate set to 50%.

2-value syntax: one value defines X and the other defines Y. Each value may be:

• One of the keyword values top, left, bottom, right. If left or right are given here, then this defines X and the other given value defines Y. If top or bottom are given, then this defines Y and the other value defines X.
• A

  <length> (en-US)

  or

  <percentage> (en-US)

  . If the other value is left or right, then this value defines Y, relative to the top edge. If the other value is top or bottom, then this value defines X, relative to the left edge. If both values are <length> or <percentage> values, then the first defines X and the second Y.

Note that:

• If one value is top or bottom, then the other value may not be top or bottom.
• If one value is left or right, then the other value may not be left or right.

This means, e.g., that top top and left right are not valid.

<bg-position>
# (en-US)
where 
<bg-position> = 
[ (en-US)
 
[ (en-US)
 left 
| (en-US)
 center 
| (en-US)
 right 
| (en-US)
 top 
| (en-US)
 bottom 
| (en-US)
 
<length-percentage>
 
] (en-US)
 
| (en-US)
 
[ (en-US)
 left 
| (en-US)
 center 
| (en-US)
 right 
| (en-US)
 
<length-percentage>
 
] (en-US)
 
[ (en-US)
 top 
| (en-US)
 center 
| (en-US)
 bottom 
| (en-US)
 
<length-percentage>
 
] (en-US)
 
| (en-US)
 
[ (en-US)
 center 
| (en-US)
 
[ (en-US)
 left 
| (en-US)
 right 
] (en-US)
 
<length-percentage>
? (en-US)
 
] (en-US)
 
&& (en-US)
 
[ (en-US)
 center 
| (en-US)
 
[ (en-US)
 top 
| (en-US)
 bottom 
] (en-US)
 
<length-percentage>
? (en-US)
 
] (en-US)
 
] (en-US)
where 
<length-percentage> = 
<length> (en-US)
 
| (en-US)
 
<percentage> (en-US)

Each of these three examples uses the

background

property to create a yellow, rectangular element containing a star image. In each example, the star is in a different position. The third example illustrates how to specify positions for two different background images within one element.

• Gecko has a bug meaning that background-position can’t be

  transitioned

  between two values containing different numbers of

  <position> (en-US)

  values, for example background-position: 10px 10px; and background-position: 20px 20px, 30px 30px; (see

  bug 1390446

  ). Firefox’s new parallel CSS engine (also known as

  Quantum CSS

  or

  Stylo

  , planned for release in Firefox 57) fixes this.

• background-position-x (en-US)

• background-position-y (en-US)

• background-position-inline

• background-position-block

• Using multiple backgrounds

• transform-origin (en-US)