CSS参考手册
逻辑属性 | Logical Properties
边界块启动 | border-block-start
这是一项实验技术
由于该技术的规格不稳定,请查看兼容性表以了解各种浏览器的使用情况。还请注意,随着规范的变化,实验技术的语法和行为在未来版本的浏览器中可能会发生变化。
border-block-start
CSS 属性是在样式表一个单一的地方设置单独的逻辑块开始 border 属性值的速记属性。
border-block-start: 1px;
border-block-start: 2px dotted;
border-block-start: medium dashed blue;
border-block-start
可用于对一个或多个的设置的值border-block-start-width
,border-block-start-style
和border-block-start-color
。它映射的物理边界取决于元素的写入模式,方向性和文本方向。它对应于border-top
,border-right
,border-bottom
,或border-left
属性根据为定义的值writing-mode
,direction
和text-orientation
。
相关属性是border-block-end
,border-inline-start
和border-inline-end
,它们定义了元素的其他边界。
Initial value |
as each of the properties of the shorthand: border-width: as each of the properties of the shorthand: border-top-width: medium border-right-width: medium border-bottom-width: medium border-left-width: medium border-style: as each of the properties of the shorthand: border-top-style: none border-right-style: none border-bottom-style: none border-left-style: none color: Varies from one browser to another |
---|---|
Applies to |
all elements |
Inherited |
no |
Media |
visual |
Computed value |
as each of the properties of the shorthand: border-width: as each of the properties of the shorthand: border-bottom-width: the absolute length or 0 if border-bottom-style is none or hidden border-left-width: the absolute length or 0 if border-left-style is none or hidden border-right-width: the absolute length or 0 if border-right-style is none or hidden border-top-width: the absolute length or 0 if border-top-style is none or hidden border-style: as each of the properties of the shorthand: border-bottom-style: as specified border-left-style: as specified border-right-style: as specified border-top-style: as specified color: If the value is translucent, the computed value will be the rgba() corresponding one. If it isn't, it will be the rgb() corresponding one. The transparent keyword maps to rgba(0,0,0,0). |
Animation type |
discrete |
Canonical order |
the unique non-ambiguous order defined by the formal grammar |
-
border-width
:作为速记的每个属性:
- [`border-top-width`](border-top-width): `medium`
- [`border-right-width`](border-right-width): `medium`
- [`border-bottom-width`](border-bottom-width): `medium`
- [`border-left-width`](border-left-width): `medium`
-
border-style
:作为速记的每个属性:
- [`border-top-style`](border-top-style): `none`
- [`border-right-style`](border-right-style): `none`
- [`border-bottom-style`](border-bottom-style): `none`
- [`border-left-style`](border-left-style): `none`
-
color
:因浏览器而异
Applies to all elements [Inherited](inheritance) no Media visual [Computed value](computed_value) as each of the properties of the shorthand:
-
border-width
:作为速记的每个属性:
- [`border-bottom-width`](border-bottom-width): the absolute length or `0` if [`border-bottom-style`](border-bottom-style) is `none` or `hidden`
- [`border-left-width`](border-left-width): the absolute length or `0` if [`border-left-style`](border-left-style) is `none` or `hidden`
- [`border-right-width`](border-right-width): the absolute length or `0` if [`border-right-style`](border-right-style) is `none` or `hidden`
- [`border-top-width`](border-top-width): the absolute length or `0` if [`border-top-style`](border-top-style) is `none` or `hidden`
-
border-style
:作为速记的每个属性:
- [`border-bottom-style`](border-bottom-style): as specified
- [`border-left-style`](border-left-style): as specified
- [`border-right-style`](border-right-style): as specified
- [`border-top-style`](border-top-style): as specified
-
color
:如果该值是半透明的,则计算出的值将是rgba()
相应的值。如果不是,那将是rgb()
相应的一个。该transparent
关键字映射到rgba(0,0,0,0)
。
Animation type discrete Canonical order the unique non-ambiguous order defined by the formal grammar
语法
值
在border-block-start
与一个或多个以下的规定,以任何顺序:
<'border-width'>
边框的宽度。看border-width
。
<'border-style'>
边框的线条样式。看border-style
。
<'color'>
边框的颜色。看color
。
形式语法
<'border-width'> || <'border-style'> || <'color'>where <color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color>where <rgb()> = rgb( [ [ <percentage>{3} | <number>{3} ] [ / <alpha-value> ]? ] | [ [ <percentage>#{3} | <number>#{3} ] , <alpha-value>? ] )<rgba()> = rgba( [ [ <percentage>{3} | <number>{3} ] [ / <alpha-value> ]? ] | [ [ <percentage>#{3} | <number>#{3} ] , <alpha-value>? ] )<hsl()> = hsl( [ <hue> <percentage> <percentage> [ / <alpha-value> ]? ] | [ <hue>, <percentage>, <percentage>, <alpha-value>? ] )<hsla()> = hsla( [ <hue> <percentage> <percentage> [ / <alpha-value> ]? ] | [ <hue>, <percentage>, <percentage>, <alpha-value>? ] )where <alpha-value> = <number> | <percentage><hue> = <number> | <angle>
例子
HTML 内容
<div>
<p class="exampleText">Example text</p>
</div>
CSS 内容
div {
background-color: yellow;
width: 120px;
height: 120px;
}
.exampleText {
writing-mode: vertical-rl;
border-block-start: 5px dashed blue;
}
规范
Specification |
Status |
Comment |
---|---|---|
CSS Logical Properties Level 1The definition of 'border-block-start' in that specification. |
Editor's Draft |
Initial definition |
浏览器兼容性
Feature |
Chrome |
Firefox (Gecko) |
Internet Explorer |
Opera |
Safari (WebKit) |
---|---|---|---|---|---|
Basic support |
No support |
41.0 (41.0)1 |
No support |
No support |
No support |
Feature |
Android |
Firefox Mobile (Gecko) |
IE Phone |
Opera Mobile |
Safari Mobile |
---|---|---|---|---|---|
Basic support |
No support |
41.0 (41.0)1 |
No support |
No support |
No support |
逻辑属性 | Logical Properties相关
层叠样式表( Cascading Style Sheets )是一种用来表现 HTML 或 XML 等文件样式的计算机语言。CSS 不仅可以静态地修饰网页,还可以配合各种脚本语言动态地对网页各元素进行格式化。