不需要记住每一条,但是需要熟悉,实际项目采用 stylelint
,prettier
配置对应规则强制统一。
- 缩进使用 2 个空格;
- 每个属性声明末尾都要加分号;
- 类名使用小写字母,以中划线分隔,使用
BEM
命名规范,为ID
和class
取通用且有意义的名字且应尽量简短。
Bem
是块(block
)、元素(element
)、修饰符(modifier
)的简写,由 Yandex
团队提出的一种前端 CSS 命名方法论。
-
中划线 :仅作为连字符使用,表示某个块或者某个子元素的多单词之间的连接记号。
__
双下划线:双下划线用来连接块和块的子元素
_
单下划线:单下划线用来描述一个块或者块的子元素的一种状态,更流行的是用 --
双中划线来表示,一般采用--
代替 _
。
<div class="el-scrollbar">
<div class="el-scrollbar__wrap">
<div class="el-scrollbar__view"></div>
<div class="el-scrollbar__view--default"></div>
<div class="el-scrollbar__view--primary"></div>
<div class="el-scrollbar__view--success"></div>
</div>
</div>
-
id
采用驼峰式命名 -
scss
中的变量、函数、混合、placeholder
采用驼峰式命名
以下几种情况需要空格:
- 属性值前
- 选择器
>
,+
,~
前后 {
前- !important
!
前 - 属性值中的
,
后 - 注释
/*
后和*/
前
.element {
color: red !important;
background-color: rgba(0, 0, 0, 0.5);
}
.element > .dialog {
...;
}
/* 注释 */
.element,
.dialog {
}
下面是推荐的属性的顺序。
[
[
"display",
"visibility",
"float",
"clear",
"overflow",
"overflow-x",
"overflow-y",
"clip",
"zoom"
],
[
"table-layout",
"empty-cells",
"caption-side",
"border-spacing",
"border-collapse",
"list-style",
"list-style-position",
"list-style-type",
"list-style-image"
],
[
"-webkit-box-orient",
"-webkit-box-direction",
"-webkit-box-decoration-break",
"-webkit-box-pack",
"-webkit-box-align",
"-webkit-box-flex"
],
[
"position",
"top",
"right",
"bottom",
"left",
"z-index"
],
[
"margin",
"margin-top",
"margin-right",
"margin-bottom",
"margin-left",
"-webkit-box-sizing",
"-moz-box-sizing",
"box-sizing",
"border",
"border-width",
"border-style",
"border-color",
"border-top",
"border-top-width",
"border-top-style",
"border-top-color",
"border-right",
"border-right-width",
"border-right-style",
"border-right-color",
"border-bottom",
"border-bottom-width",
"border-bottom-style",
"border-bottom-color",
"border-left",
"border-left-width",
"border-left-style",
"border-left-color",
"-webkit-border-radius",
"-moz-border-radius",
"border-radius",
"-webkit-border-top-left-radius",
"-moz-border-radius-topleft",
"border-top-left-radius",
"-webkit-border-top-right-radius",
"-moz-border-radius-topright",
"border-top-right-radius",
"-webkit-border-bottom-right-radius",
"-moz-border-radius-bottomright",
"border-bottom-right-radius",
"-webkit-border-bottom-left-radius",
"-moz-border-radius-bottomleft",
"border-bottom-left-radius",
"-webkit-border-image",
"-moz-border-image",
"-o-border-image",
"border-image",
"-webkit-border-image-source",
"-moz-border-image-source",
"-o-border-image-source",
"border-image-source",
"-webkit-border-image-slice",
"-moz-border-image-slice",
"-o-border-image-slice",
"border-image-slice",
"-webkit-border-image-width",
"-moz-border-image-width",
"-o-border-image-width",
"border-image-width",
"-webkit-border-image-outset",
"-moz-border-image-outset",
"-o-border-image-outset",
"border-image-outset",
"-webkit-border-image-repeat",
"-moz-border-image-repeat",
"-o-border-image-repeat",
"border-image-repeat",
"padding",
"padding-top",
"padding-right",
"padding-bottom",
"padding-left",
"width",
"min-width",
"max-width",
"height",
"min-height",
"max-height"
],
[
"font",
"font-family",
"font-size",
"font-weight",
"font-style",
"font-variant",
"font-size-adjust",
"font-stretch",
"font-effect",
"font-emphasize",
"font-emphasize-position",
"font-emphasize-style",
"font-smooth",
"line-height",
"text-align",
"-webkit-text-align-last",
"-moz-text-align-last",
"-ms-text-align-last",
"text-align-last",
"vertical-align",
"white-space",
"text-decoration",
"text-emphasis",
"text-emphasis-color",
"text-emphasis-style",
"text-emphasis-position",
"text-indent",
"-ms-text-justify",
"text-justify",
"letter-spacing",
"word-spacing",
"-ms-writing-mode",
"text-outline",
"text-transform",
"text-wrap",
"-ms-text-overflow",
"text-overflow",
"text-overflow-ellipsis",
"text-overflow-mode",
"-ms-word-wrap",
"word-wrap",
"-ms-word-break",
"word-break"
],
[
"color",
"background",
"filter:progid:DXImageTransform.Microsoft.AlphaImageLoader",
"background-color",
"background-image",
"background-repeat",
"background-attachment",
"background-position",
"-ms-background-position-x",
"background-position-x",
"-ms-background-position-y",
"background-position-y",
"-webkit-background-clip",
"-moz-background-clip",
"background-clip",
"background-origin",
"-webkit-background-size",
"-moz-background-size",
"-o-background-size",
"background-size"
],
[
"outline",
"outline-width",
"outline-style",
"outline-color",
"outline-offset",
"opacity",
"filter:progid:DXImageTransform.Microsoft.Alpha(Opacity",
"-ms-filter:\\'progid:DXImageTransform.Microsoft.Alpha",
"-ms-interpolation-mode",
"-webkit-box-shadow",
"-moz-box-shadow",
"box-shadow",
"filter:progid:DXImageTransform.Microsoft.gradient",
"-ms-filter:\\'progid:DXImageTransform.Microsoft.gradient",
"text-shadow"
],
[
"-webkit-transition",
"-moz-transition",
"-ms-transition",
"-o-transition",
"transition",
"-webkit-transition-delay",
"-moz-transition-delay",
"-ms-transition-delay",
"-o-transition-delay",
"transition-delay",
"-webkit-transition-timing-function",
"-moz-transition-timing-function",
"-ms-transition-timing-function",
"-o-transition-timing-function",
"transition-timing-function",
"-webkit-transition-duration",
"-moz-transition-duration",
"-ms-transition-duration",
"-o-transition-duration",
"transition-duration",
"-webkit-transition-property",
"-moz-transition-property",
"-ms-transition-property",
"-o-transition-property",
"transition-property",
"-webkit-transform",
"-moz-transform",
"-ms-transform",
"-o-transform",
"transform",
"-webkit-transform-origin",
"-moz-transform-origin",
"-ms-transform-origin",
"-o-transform-origin",
"transform-origin",
"-webkit-animation",
"-moz-animation",
"-ms-animation",
"-o-animation",
"animation",
"-webkit-animation-name",
"-moz-animation-name",
"-ms-animation-name",
"-o-animation-name",
"animation-name",
"-webkit-animation-duration",
"-moz-animation-duration",
"-ms-animation-duration",
"-o-animation-duration",
"animation-duration",
"-webkit-animation-play-state",
"-moz-animation-play-state",
"-ms-animation-play-state",
"-o-animation-play-state",
"animation-play-state",
"-webkit-animation-timing-function",
"-moz-animation-timing-function",
"-ms-animation-timing-function",
"-o-animation-timing-function",
"animation-timing-function",
"-webkit-animation-delay",
"-moz-animation-delay",
"-ms-animation-delay",
"-o-animation-delay",
"animation-delay",
"-webkit-animation-iteration-count",
"-moz-animation-iteration-count",
"-ms-animation-iteration-count",
"-o-animation-iteration-count",
"animation-iteration-count",
"-webkit-animation-direction",
"-moz-animation-direction",
"-ms-animation-direction",
"-o-animation-direction",
"animation-direction"
],
[
"content",
"quotes",
"counter-reset",
"counter-increment",
"resize",
"cursor",
"-webkit-user-select",
"-moz-user-select",
"-ms-user-select",
"user-select",
"nav-index",
"nav-up",
"nav-right",
"nav-down",
"nav-left",
"-moz-tab-size",
"-o-tab-size",
"tab-size",
"-webkit-hyphens",
"-moz-hyphens",
"hyphens",
"pointer-events"
]
]
以下几种情况需要空行:
- 文件最后保留一个空行
}
后最好跟一个空行,包括 scss 中嵌套的规则
颜色 16 进制用小写字母;颜色 16 进制尽量用简写。
/* 不推荐 */
.element {
color: ~#ABCDEF;
background-color: #001122;
}
/* 推荐 */
.element {
color: #abcdef;
background-color: #012;
}
写属性值的时候尽量使用缩写,常见的属性简写包括:
font
background
transition
animation
/* 不推荐 */
.element {
transition-delay: 2s;
transition-timing-function: linear;
transition-duration: 1s;
transition-property: opacity;
}
/* 推荐 */
.element {
transition: opacity 1s linear 2s;
}
尽量将媒体查询的规则靠近与他们相关的规则,不要将他们一起放到一个独立的样式文件中,或者丢在文档的最底部,这样做只会让大家以后更容易忘记他们。
.element {
...;
}
.element-avatar {
...;
}
@media (min-width: 480px) {
.element {
...;
}
.element-avatar {
...;
}
}
统一使用单引号;url
的内容要用引号;属性选择器中的属性值需要引号。
element:after {
content: '';
background-image: url('logo.png');
}
li[data-type='single'] {
...;
}
注释统一用/* */
(scss
中也尽量少用//
)
缩进与下一行代码保持一致;
可位于一个代码行的末尾,与代码间隔一个空格。
/* 注释 */
.modal-header {
...;
}
-
不允许有空的规则;
-
元素选择器用小写字母;
-
建议去掉小数点前面的
0
; -
去掉数字中不必要的小数点和末尾的
0
; -
属性值
0
后面不要加单位; -
同个属性不同前缀的写法需要在垂直方向保持对齐;
-
无前缀的标准属性应该写在有前缀的属性后面;
-
不要在同个规则里出现重复的属性,如果重复的属性是连续的则没关系;
-
不要在一个文件里出现两个相同的规则;
-
用
border: 0;
代替border: none;
; -
选择器不要超过 4 层(在
scss
中如果超过 4层应该考虑用嵌套的方式来写); -
发布的代码中不要有 @import;
-
尽量少用
*
选择器。