非常教程

CSS参考手册

基本框模型 | Basic Box Model

自动 | auto

width 属性指定了元素内容区的宽度。默认情况下,该属性定义了内容区域的宽度。如果box-sizing设置为border-box,则确定边框区域的宽度。

/* <length> values */
width: 300px;
width: 25em;

/* <percentage> value */
width: 75%;

/* Keyword values */
width: 25em border-box;
width: 75% content-box;
width: max-content;
width: min-content;
width: available;
width: fit-content;
width: auto;

/* Global values */
width: inherit;
width: initial;
width: unset;

min-widthmax-width属性覆盖width

初始值

auto

适用元素

all elements but non-replaced inline elements, table rows, and row groups

是否是继承属性

no

Percentages

refer to the width of the containing block

适用媒体

visual

计算值

a percentage or auto or the absolute length

Animation type

a length, percentage or calc();

正规顺序

the length or percentage before the keyword, if both are present

语法

width属性被指定为:

  • 以下关键字值之一:availablemin-contentmax-contentfit-contentauto
  • <length><percentage>。这可以选择跟随以下关键字之一:border-boxcontent-box

<length>可能的长度单位见<length>.

<percentage>指定为包含块宽度的<percentage>.

border-box如出现, 之前的<length><percentage>应用到元素的边框盒子.

content-box如出现, 之前的<length><percentage>应用到元素的内容盒子.

auto浏览器将会为指定的元素计算并选择一个宽度.

fill使用 fill-available 行内尺寸或者 fill-available 块级尺寸其中一种来作为合适的书写模式。max-content固有的首选宽度.

min-content固有的最小宽度.

available包含块的宽度减去水平 margin, border 和 padding.

fit-content以下两种情况下的较大值:

  • 固有的最小宽度

  • 固有首选宽度(max-content)和可用宽度(available)的较小值

正式语法

[ <length> | <percentage> ] && [ border-box | content-box ]? | available | min-content | max-content | fit-content | auto

示例

默认宽度

p.goldie {
  background: gold;
}
<p class="goldie">The Mozilla community produces a lot of great software.</p>

px 和 em

.px_length {
  width: 200px;
  background-color: red;
  color: white;
  border: 1px solid black;
}

.em_length {
  width: 20em;
  background-color: white;
  color: red;
  border: 1px solid black;
}
<div class="px_length">Width measured in px</div>
<div class="em_length">Width measured in em</div>

百分比

.percent {
  width: 20%;
  background-color: silver;
  border: 1px solid red;
}
<div class="percent">Width in percentage</div>

max-content

p.maxgreen {
  background: lightgreen;
  width: intrinsic;           /* Safari/WebKit uses a non-standard name */
  width: -moz-max-content;    /* Firefox/Gecko */
  width: -webkit-max-content; /* Chrome */
}
<p class="maxgreen">The Mozilla community produces a lot of great software.</p>

min-content

p.minblue {
  background: lightblue;
  width: -moz-min-content;    /* Firefox */
  width: -webkit-min-content; /* Chrome */
}
<p class="minblue">The Mozilla community produces a lot of great software.</p>

规范

Specification

Status

Comment

CSS Basic Box ModelThe definition of 'width' in that specification.

Working Draft

Added the max-content, min-content, available, fit-content, border-box, content-box keywords.

CSS TransitionsThe definition of 'width' in that specification.

Working Draft

Lists width as animatable.

CSS Level 2 (Revision 1)The definition of 'width' in that specification.

Recommendation

Precises on which element it applies to.

CSS Level 1The definition of 'width' in that specification.

Recommendation

Initial definition

CSS Intrinsic & Extrinsic Sizing Module Level 3The definition of 'width' in that specification.

Working Draft

Adds new sizing keywords for width and height.

浏览器兼容性

Feature

Chrome

Edge

Firefox (Gecko)

Internet Explorer

Opera

Safari (WebKit)

Basic support

(Yes)

(Yes)

1.0 (1.7 or earlier)

4

3.5

1.0 (85)

Animatability

?

?

16.0 (16.0)

?

?

?

max-content

22.0 -webkit 46.0 1

No support

3.0 (1.9)-moz

?

15 -webkit

2.0 (421) (intrinsic value) 6.1 -webkit

min-content

22.0 4 -webkit 46.0 1

No support

3.0 (1.9) -moz

?

15 -webkit

2.0 (421) (min-intrinsic value) 6.1 -webkit

available

No support

No support

3.0 (1.9) -moz

?

?

?1

fill-available

22.0 -webkit

No support

No support

?

?

6.1 -webkit

fit-content

22.0 4 -webkit 46.0 1

No support

3.0 (1.9) -moz

?

15 -webkit

6.1 -webkit2

border-box and content-box

No support

No support

No support

No support

No support

No support

fill

46.0

No support

Feature

Android

Android Webview

Edge

Firefox Mobile (Gecko)

IE Phone

Opera Mobile

Safari Mobile

Chrome for Android

Basic support

?

(Yes)

(Yes)

?

?

?

?

(Yes)

Animatability

?

?

?

16.0 (16.0)

?

?

?

?

max-content

No support

46.0 1

No support

?

?

?

?

46.0 1

min-content

No support

46.0 1

No support

?

?

?

?

46.0 1

available

?

?

No support

?

?

?

?

?

fill-available

No support

46.0 1

No support

?

?

?

?

46.0 1

fit-content

No support

46.0 1

No support

?

?

?

?

46.0 1

border-box and content-box

?

?

No support

?

?

?

?

?

fill

No support

46.0

No support

?

46.0

CSS

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。

CSS目录

1.动画和转换 | Animations & Transitions
2.背景和边框 | Backgrounds & Borders
3.基本框模型 | Basic Box Model
4.基本用户界面 | Basic User Interface
5.框对齐 | Box Alignment
6. 级联和继承 | Cascading & Inheritance
7.颜色 | Color
8. 合成与混合 | Compositing & Blending
9.条件和规则 | Conditional Rules
10.计数器样式 | Counter Styles
11.设备适配 | Device Adaptation
12.扩展 | Extensions
13.滤镜效果 | Filter Effects
14.灵活的框布局 | Flexible Box Layout
15.字体 | Fonts
16.片段模块 | Fragmentation
17.全屏 API | Fullscreen API
18. 生成内容 | Generated Content
19.网格布局 | Grid Layout
20.图像值 | Image Values
21.初始线格局 | Inline Layout
22.列表和计数器 | Lists & Counters
23.逻辑属性 | Logical Properties
24.面具 | Masking
25.媒体查询 | Media Queries
26.杂项 | Miscellaneous
27.Miscellaneous Level 1
28.Miscellaneous Level 2
29.运动路径 | Motion Path
30. 多列布局 | Multi-column Layout
31.命名空间 | Namespaces
32.项目模型 | Object Model View
33.网页媒体 | Paged Media
34.定位布局 | Positioned Layout
35.伪元素 | Pseudo-
36.节奏大小 | Rhythmic Sizing
37. Ruby布局 | Ruby Layout
38.可缩放矢量图形 | Scalable Vector Graphics
39.滚动快照 | Scroll Snap
40.选择 | Selectors
41.形状 | Shapes
42.文本 | Text
43.文字装饰 | Text Decoration
44.变换 | Transforms
45.值和单位 | Values & Units
46.变量 | Variables
47.写入模型 | Writing Modes
48.CSS 教程
49.CSS 创建
50.CSS Id 和 Class选择器
51.CSS 简介
52.CSS 盒子模型
53.CSS Table(表格)
54.CSS 列表样式(ul)
55.CSS 链接(link)
56.CSS Fonts(字体)
57.CSS Text(文本)
58.CSS Backgrounds(背景)
59.CSS Display(显示) 与 Visibility(可见性)
60.CSS 尺寸 (Dimension)
61.CSS 分组和嵌套
62.CSS 轮廓(outline)属性
63.CSS Border(边框)
64.CSS 图像透明/不透明
65.CSS 导航栏
66.CSS 伪元素
67.CSS 伪类
68.CSS Float(浮动)
69.CSS Position(定位)
70.CSS 总结
71.CSS 属性选择器
72.CSS 媒体类型
73.CSS 图像拼合技术
74.CSS 实例
75.CSS 组合选择符
76.响应式 Web 设计 – 框架
77.响应式 Web 设计 – 视频(Video)
78.CSS 提示工具(Tooltip)
79.CSS 布局 Overflow
80.CSS 计数器
81.CSS 表单