样式: CSS: 选择器 about blog

[xvno]

属性选择器

[attr="value"]

毋庸置疑, 属性值全等 "value"
a[target=_blank]

• <a href="http://vno.io" target="_blank">vno's blog</a>

[attr~="value"]

属性值包含独立的单词 "value"
[title~=dog]会选中

• <img src="husky.jpg" title="husky dog">
• <img src="teddy.gif" title="dog">

[attr|="value"]

属性值包含起始位置为"value"或"value-"的元素,
如 [data-class|="showme"] 选中

• <p data-class="showme">...</p>
• <p data-class="showme-something">...</p>

[attr^="value]

attr值以"value"开头的, 类似于重则表达式的匹配

[class^="top"]

• <h1 class="top-header">Welcome</h1>
• <p class="top-text">Hello world!</p>
• <p class="topcontent">Are you learning CSS?</p>

[attr$="value"]

attr值以"test"结尾的, 类比正则
[class$="og"]

• <img src="husky.jpg" title="husky dog">
• <img src="teddy.gif" title="dog">
• <img src="frog.gif" title="frog">

[attr*="value"]

属性attr值中包含"value"的元素
[data-class*="me"]

• <p data-class="me">...</p>
• <p data-class="melord">...</p>
• <p data-class="showme">...</p>
• <p data-class="showmesomething">...</p>
• <p data-class="show-me-something">...</p>

[xvno]

普通选择器

.className 类名, 以点 . 引导

• .top
• .nav
• footer

#idName id值, 以 # 引导

• #userName
• #target

tagName html标签名

• div
• p

[xvno]

层次选择器

A, B都为正常选择器(tagName, #idName, #className, [attr]...), 都是通过A的位置定位B

A, B

A或B, 并集选择器

A B

后代选择器 B wrapped in A, 可以有其他elements多层包裹B

A > B

直接后代选择器, 或子选择器, A is parent of B

A + B 紧邻/后邻选择器

, A next to B, B closely behind A,

A ~ B 同级元素

后部兄弟选择器, AB siblings, B behind A

[xvno]

伪元素 & 伪类

伪元素

伪元素	示例	说明
::after	p::after	Insert something after the content of each element
::before	p::before	Insert something before the content of each element
::first-letter	p::first-letter	Selects the first letter of every element
::first-line	p::first-line	Selects the first line of every element
::selection	::selection	Selects the portion of an element that is selected by a user
::placeholder	input::placeholder	Selects input elements with placeholder text

伪类

伪类名	示例	说明
:active	a:active	Selects the active link
:checked	input:checked	Selects every checked element
:default	input:default	Selects the default element
:disabled	input:disabled	Selects every disabled element
:empty	p:empty	Selects every element that has no children (including text nodes)
:enabled	input:enabled	Selects every enabled element
:first-child	p:first-child	Selects every element that is the first child of its parent
:first-of-type	p:first-of-type	Selects every element that is the first element of its parent
:focus	input:focus	Selects the input element which has focus
:hover	a:hover	Selects links on mouse over
:in-range	input:in-range	Selects input elements with a value within a specified range
:indeterminate	input:indeterminate	Selects input elements that are in an indeterminate state
:invalid	input:invalid	Selects all input elements with an invalid value
:lang(language)	p:lang(it)	Selects every element with a lang attribute equal to "it" (Italian)
:last-child	p:last-child	Selects every element that is the last child of its parent
:last-of-type	p:last-of-type	Selects every element that is the last element of its parent
:link	a:link	Selects all unvisited links
:not(selector)	:not(p)	Selects every element that is not a element
:nth-child(n)	p:nth-child(2)	Selects every element that is the second child of its parent
:nth-last-child(n)	p:nth-last-child(2)	Selects every element that is the second child of its parent, counting from the last child
:nth-last-of-type(n)	p:nth-last-of-type(2)	Selects every element that is the second element of its parent, counting from the last child
:nth-of-type(n)	p:nth-of-type(2)	Selects every element that is the second element of its parent
:only-of-type	p:only-of-type	Selects every element that is the only element of its parent
:only-child	p:only-child	Selects every element that is the only child of its parent
:optional	input:optional	Selects input elements with no "required" attribute
:out-of-range	input:out-of-range	Selects input elements with a value outside a specified range
:read-only	input:read-only	Selects input elements with the "readonly" attribute specified
:read-write	input:read-write	Selects input elements with the "readonly" attribute NOT specified
:required	input:required	Selects input elements with the "required" attribute specified
:root	:root	Selects the document's root element
:target	#news:target	Selects the current active #news element (clicked on a URL containing that anchor name)
:valid	input:valid	Selects all input elements with a valid value
:visited	a:visited	Selects all visited links

[xvno]

组合选择器

这类选择器实在太多, 可以按照{ 普通选择器, 位置/层次选择器, 属性选择器 }随意组合

A.B

A#C

A.B#C

A .B

A #C

A .B #C

A .B #C > li

...