尝试一下
background: green;
background: content-box radial-gradient(crimson, skyblue);
background: no-repeat url("/shared-assets/images/examples/lizard.png");
background: left 5% / 15% 60% repeat-x
url("/shared-assets/images/examples/star.png");
background:
center / contain no-repeat
url("/shared-assets/images/examples/firefox-logo.svg"),
#eee 35% url("/shared-assets/images/examples/lizard.png");
<section id="default-example">
<div id="example-element"></div>
</section>
#example-element {
min-width: 100%;
min-height: 100%;
padding: 10%;
}
此属性是一个简写属性，可以在一次声明中定义一个或多个属性：background-clip、background-color、background-image、background-origin、background-position、background-repeat、background-size 和 background-attachment。
对于所有简写属性，任何没有被指定的值都会被设定为它们的 初始值。
语法
css
/* 使用 <background-color> */
background: green;
/* 使用 <bg-image> 和 <repeat-style> */
background: url("test.jpg") repeat-y;
/* 使用 <box> 和 <background-color> */
background: border-box red;
/* 将背景设为一张居中放大的图片 */
background: no-repeat center/80% url("../img/image.png");
background 属性被指定多个背景层时，使用逗号分隔每个背景层。
每一层的语法如下：
-
在每一层中，下列的值可以出现 0 次或 1 次：
-
<bg-size>只能紧接着<position>出现，以"/"分割，如： "center/80%". -
<box>可能出现 0 次、1 次或 2 次。如果出现 1 次，它同时设定background-origin和background-clip。如果出现 2 次，第一次的出现设置background-origin，第二次的出现设置background-clip。 -
<background-color>只能被包含在最后一层。
备注：background-color 只能在 background 的最后一个属性上定义，因为整个元素只有一种背景颜色。
值
下面的一个或多个值，可以按任意顺序放置：
标准语法
background =
<bg-layer>#? , <final-bg-layer>
<bg-layer> =
<bg-image> ||
<bg-position> [ / <bg-size> ]? ||
<repeat-style> ||
<attachment> ||
<bg-clip> ||
<visual-box>
<final-bg-layer> =
<bg-image> ||
<bg-position> [ / <bg-size> ]? ||
<repeat-style> ||
<attachment> ||
<bg-clip> ||
<visual-box> ||
<'background-color'>
<bg-image> =
<image> |
none
<bg-position> =
<position> |
<position-three>
<bg-size> =
[ <length-percentage [0,∞]> | auto ]{1,2} |
cover |
contain
<repeat-style> =
repeat-x |
repeat-y |
repeat-block |
repeat-inline |
<repetition>{1,2}
<attachment> =
scroll |
fixed |
local
<bg-clip> =
<visual-box> |
[ border-area || text ]
<visual-box> =
content-box |
padding-box |
border-box
<background-color> =
<color>
<image> =
<url> |
<image()> |
<image-set()> |
<cross-fade()> |
<element()> |
<gradient>
<position> =
<position-one> |
<position-two> |
<position-four>
<position-three> =
[ left | center | right ] && [ [ top | bottom ] <length-percentage> ] |
[ [ left | right ] <length-percentage> ] && [ top | center | bottom ]
<length-percentage> =
<length> |
<percentage>
<repetition> =
repeat |
space |
round |
no-repeat
<image()> =
image( <image-tags>? [ <image-src>? , <color>? ]! )
<image-set()> =
image-set( <image-set-option># )
<cross-fade()> =
cross-fade( <cf-image># )
<element()> =
element( <id-selector> )
<position-one> =
left |
center |
right |
top |
bottom |
x-start |
x-end |
y-start |
y-end |
block-start |
block-end |
inline-start |
inline-end |
<length-percentage>
<position-two> =
[ left | center | right | x-start | x-end ] && [ top | center | bottom | y-start | y-end ] |
[ left | center | right | x-start | x-end | <length-percentage> ] [ top | center | bottom | y-start | y-end | <length-percentage> ] |
[ block-start | center | block-end ] && [ inline-start | center | inline-end ] |
[ start | center | end ]{2}
<position-four> =
[ [ left | right | x-start | x-end ] <length-percentage> ] && [ [ top | bottom | y-start | y-end ] <length-percentage> ] |
[ [ block-start | block-end ] <length-percentage> ] && [ [ inline-start | inline-end ] <length-percentage> ] |
[ [ start | end ] <length-percentage> ]{2}
<image-tags> =
ltr |
rtl
<image-src> =
<url> |
<string>
<image-set-option> =
[ <image> | <string> ] [ <resolution> || type( <string> ) ]?
<cf-image> =
[ <image> | <color> ] &&
<percentage [0,100]>?
<id-selector> =
<hash-token>
示例
HTML
html
<p class="topbanner">
Starry sky<br />
Twinkle twinkle<br />
Starry sky
</p>
<p class="warning">Here is a paragraph</p>
<p></p>
CSS
css
.warning {
background: red;
}
.topbanner {
background: url("star-solid.gif") #99f repeat-y fixed;
}
结果
规范
| 规范 |
|---|
| CSS Backgrounds and Borders Module Level 3 # background |