1 _nth-child系列
:nth-child(index)

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>nth-Child</title>
<style type="text/css">
ul > li:nth-child(3) {
background: #f00;
}
/*
ul > li:nth-child(2n) {
background: #ff0;
}
ul > li:nth-child(2n+1) {
background: #0f0;
}
ul > li:nth-child(n+4) {
background: #abcdef;
}
ul > li:nth-child(odd) {
background: red;
}
ul > li:nth-child(even) {
background: blue;
}
*/
</style>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
</ul>
<hr>
<div>0-1</div>
<div>0-2</div>
<div>0-3</div>
<hr>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
</ul>
</body>
</html>
2 :first-child 第一个孩子
:first-child {
border: 1px solid;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>First-Child</title>
<style type="text/css">
:first-child {
border: 1px solid;
}
</style>
</head>
<body>
<div id="wrap">
<div>0-1</div>
<div>0-2</div>
<div>0-3</div>
</div>
<div>1-1</div>
</body>
</html>
3 #wrap > div:first-child
#wrap > div:first-child {
color: deeppink;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>First-Child</title>
<style type="text/css">
#wrap > div:first-child {
color: deeppink;
}
</style>
</head>
<body>
<div>0-1</div>
<div>0-2</div>
<div>0-3</div>
<div id="wrap">
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</div>
<div>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</div>
</body>
</html>
4 :last-child 最后一个孩子
:last-child {
border: 1px solid;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Last-Child</title>
<style type="text/css">
:last-child {
border: 1px solid;
}
</style>
</head>
<body>
<div id="wrap">
<div class="inner">1</div>
<div class="inner">2</div>
<div class="inner">3</div>
<div class="inner">4</div>
</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
</body>
</html>
5 #wrap > div:last-child
#wrap > div:last-child {
border: 1px solid;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Last-Child</title>
<style type="text/css">
#wrap > div:last-child {
border: 1px solid;
}
</style>
</head>
<body>
<div id="wrap">
<div class="inner">1</div>
<div class="inner">2</div>
<div class="inner">3</div>
<div class="inner">4</div>
</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
<div>wrap同级</div>
</body>
</html>
6 nth-last-child(3) 元素倒数坐标
ul > li:nth-last-child(3) {
background: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>nth-Child</title>
<style type="text/css">
ul > li:nth-last-child(3) {
background: #f00;
}
</style>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
</ul>
<hr>
<div>0-1</div>
<div>0-2</div>
<div>0-3</div>
<div>
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</div>
<div>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</div>
<hr>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
<li>9</li>
</ul>
</body>
</html>
7 article:only-child 只有一个孩子
article:only-child {
background: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>only-child</title>
<style type="text/css">
article:only-child {
background: #f00;
}
</style>
</head>
<body>
<section>
<article>1</article>
<article>2</article>
</section>
<section>
<article>3</article>
</section>
<section>
<div>4</div>
<article>5</article>
<div>6</div>
</section>
<section>
<div>7</div>
<article>8</article>
<article>9</article>
<div>10</div>
</section>
</body>
</html>
nth-of-type
div:nth-of-type(index)
div:nth-of-type(2) {
color: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>nth-of-type</title>
<style type="text/css">
/*div:nth-child(2) {
color: #f00;
}*/
div:nth-of-type(2) {
color: #f00;
}
</style>
</head>
<body>
<div>0-1</div>
<section>
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</section>
<div>0-2</div>
<div>0-3</div>
<section>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</section>
</body>
</html>
first-of-type 一个孩子或者第一个孩子
div:first-of-type {
color: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>First-of-type</title>
<style type="text/css">
div:first-of-type {
color: #f00;
}
</style>
</head>
<body>
<div>0-1</div>
<section>
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</section>
<div>0-2</div>
<div>0-3</div>
<section>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</section>
</body>
</html>
Last-of-type 最后一个孩子
div:last-of-type {
color: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Last-of-type</title>
<style type="text/css">
div:last-of-type {
color: #f00;
}
</style>
</head>
<body>
<div>0-1</div>
<section>
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</section>
<div>0-2</div>
<div>0-3</div>
<section>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</section>
</body>
</html>
nth-last-of-type 中间孩子或第一个孩子

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>nth-Last-of-type</title>
<style type="text/css">
/*div:nth-last-child(2) {
color: #f00;
}*/
div:nth-last-of-type(2) {
color: #f00;
}
</style>
</head>
<body>
<div>0-1</div>
<section>
<div>1-1</div>
<div>1-2</div>
<div>1-3</div>
</section>
<div>0-2</div>
<div>0-3</div>
<section>
<div>2-1</div>
<div>2-2</div>
<div>2-3</div>
</section>
</body>
</html>
only-of-type 唯一的一个标签元素
article:only-of-type {
background: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>only-of-type</title>
<style type="text/css">
article:only-of-type {
background: #f00;
}
</style>
</head>
<body>
<section>
<article>1</article>
<article>2</article>
</section>
<section>
<article>3</article>
</section>
<section>
<div>4</div>
<article>5</article>
<div>6</div>
</section>
<section>
<div>7</div>
<article>8</article>
<article>9</article>
<div>10</div>
</section>
</body>
</html>
not(元素节点)
div > a:not(:last-of-type) {
border-right: 1px solid red;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>not</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
border: none;
}
a {
text-decoration: none;
color: #333;
font-size: 14px;
display: block;
float: left;
width: 100px;
height: 30px;
}
div {
width: 800px;
margin: 0 auto;
}
div > a:not(:last-of-type) {
border-right: 1px solid red;
}
</style>
</head>
<body>
<div>
<a href="#">first</a>
<a href="#">second</a>
<a href="#">third</a>
<a href="#">fourth</a>
<a href="#">fifth</a>
</div>
</body>
</html>
empty
div:empty {
background: #f00;
}

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>empty</title>
<style type="text/css">
div {
height: 200px;
background: #abcdef;
}
div:empty {
background: #f00;
}
</style>
</head>
<body>
<div></div>
<div>Second</div>
<div></div>
<div>Third</div>
</body>
</html>
