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css选择器.html
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<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="generator" content="Movable Type 5.2.2">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="http://www.ruanyifeng.com/blog/styles.css" type="text/css">
<link rel="start" href="http://www.ruanyifeng.com/blog/" title="Home">
<link rel="alternate" type="application/atom+xml" title="Recent Entries" href="http://feeds.feedburner.com/ruanyifeng">
<script src="https://hm.baidu.com/hm.js?f89e0235da0841927341497d774e7b15"></script>
<script async="" src="//www.google-analytics.com/analytics.js"></script>
<script type="text/javascript" src="http://www.ruanyifeng.com/blog/mt.js"></script>
<link rel="prev" href="http://www.ruanyifeng.com/blog/2009/03/rpx_trial_thoughts.html" title="Openid托管服务RPX试用感想">
<link rel="next" href="http://www.ruanyifeng.com/blog/2009/03/my_bitter_friendship_with_mr_xiao_guangyan.html" title="白介夫：我与萧光琰的苦涩友谊（转贴）">
<title>CSS选择器笔记</title>
<script src="//static.bshare.cn/b/components/bsStatic.js?v=20180226" type="text/javascript" charset="utf-8"></script>
<script src="//static.bshare.cn/js/libs/fingerprint2.min.js" type="text/javascript" charset="utf-8"></script>
<script src="//static.bshare.cn/b/engines/bs-engine.js?v=20180226" type="text/javascript" charset="utf-8"></script>
<style type="text/css">
a.bshareDiv,
#bsPanel,
#bsMorePanel,
#bshareF {
border: none;
background: none;
padding: 0;
margin: 0;
font: 12px Helvetica, Calibri, Tahoma, Arial, 宋体, sans-serif;
line-height: 14px;
}
#bsPanel div,
#bsMorePanel div,
#bshareF div {
display: block;
}
.bsRlogo .bsPopupAwd,
.bsRlogoSel .bsPopupAwd,
.bsLogo .bsPopupAwd,
.bsLogoSel .bsPopupAwd {
line-height: 16px !important;
}
a.bshareDiv div,
#bsFloatTab div {
*display: inline;
zoom: 1;
display: inline-block;
}
a.bshareDiv img,
a.bshareDiv div,
a.bshareDiv span,
a.bshareDiv a,
#bshareF table,
#bshareF tr,
#bshareF td {
text-decoration: none;
background: none;
margin: 0;
padding: 0;
border: none;
line-height: 1.2
}
a.bshareDiv span {
display: inline;
float: none;
}
div.buzzButton {
cursor: pointer;
font-weight: bold;
}
.buzzButton .shareCount a {
color: #333
}
.bsStyle1 .shareCount a {
color: #fff
}
span.bshareText {
white-space: nowrap;
}
span.bshareText:hover {
text-decoration: underline;
}
a.bshareDiv .bsPromo,
div.bshare-custom .bsPromo {
display: none;
position: absolute;
z-index: 100;
}
a.bshareDiv .bsPromo.bsPromo1,
div.bshare-custom .bsPromo.bsPromo1 {
width: 51px;
height: 18px;
top: -18px;
left: 0;
line-height: 16px;
font-size: 12px !important;
font-weight: normal !important;
color: #fff;
text-align: center;
background: url(//static.bshare.cn/frame/images/bshare_box_sprite2.gif) no-repeat 0 -606px;
}
div.bshare-custom .bsPromo.bsPromo2 {
background: url(//static.bshare.cn/frame/images/bshare_promo_sprite.gif) no-repeat;
cursor: pointer;
}
</style>
<style type="text/css">
.bsBox {
display: none;
z-index: 100000001;
font-size: 12px;
background: url(//static.bshare.cn/frame/images//background-opaque-dark.gif) !important;
padding: 6px !important;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
}
.bsClose {
_overflow: hidden;
cursor: pointer;
position: absolute;
z-index: 10000000;
color: #666;
font-weight: bold;
font-family: Helvetica, Arial;
font-size: 14px;
line-height: 20px;
}
.bsTop {
color: #666;
background: #f2f2f2;
height: 24px;
line-height: 24px;
border-bottom: 1px solid #e8e8e8;
}
.bsTop span {
float: left;
}
.bsFrameDiv,
#bsMorePanel {
border: none;
background: #fff;
}
.bsReturn {
float: right;
*margin-right: 20px;
margin-right: 36px;
text-align: right;
cursor: pointer;
line-height: 24px;
color: #666;
opacity: 0.5;
}
#bsReturn:hover {
text-decoration: underline;
opacity: 1;
}
</style>
<script src="//static.bshare.cn/b/components/bsMore.js?v=20180226" type="text/javascript" charset="utf-8"></script>
<script src="//static.bshare.cn/b/styles/bshareS1.js?v=20180226" type="text/javascript" charset="utf-8"></script>
<style type="text/css">
div.bsClear {
clear: both;
height: 0;
line-height: 0;
overflow: hidden;
font-size: 0;
}
.bsSearchDiv {
padding: 5px 15px;
background-color: #fafafa;
}
.bFind-wrapper-top {
background: #fff;
border-color: #ccc #aaa #aaa #ccc;
border-style: solid;
border-width: 1px;
height: 16px;
padding: 4px;
margin: 0;
}
.bFind-wrapper-top input {
padding: 0 !important;
border: none !important;
box-shadow: none !important;
line-height: 16px !important;
}
.bFind-placeholder {
background: url("//static.bshare.cn/css/images/search-icon.gif") no-repeat;
display: block;
float: left;
height: 16px;
width: 16px;
}
.bFind {
background: none;
border: none;
float: left;
font-size: 11px !important;
height: 16px !important;
margin-left: 3px;
outline: none;
padding: 0;
width: 400px;
}
.bsPlatDiv {
height: 322px;
background: #fff;
overflow: auto;
padding: 0 15px;
}
#bsLogoList {
display: block;
list-style: none;
overflow: hidden;
margin: 0;
padding: 0;
}
#bsLogoList li {
float: left;
display: inline-block;
width: 71px;
text-align: center;
font-size: 12px;
height: 80px;
margin: 0 !important;
}
#bsLogoList .bsPlatIcon {
cursor: pointer;
display: block !important;
text-align: center;
}
#bsLogoList .bsPlatImg {
width: 32px;
height: 32px;
border: none !important;
display: inline-block;
}
#bsLogoList .bsPlatImg:hover {
-moz-border-radius: 7px;
-webkit-border-radius: 7px;
border-radius: 7px;
box-shadow: 0 0 15px #a7a8ac;
}
#bsLogoList .bsPlatName {
white-space: nowrap;
text-overflow: ellipsis;
overflow: hidden;
text-align: center;
color: #333 !important;
margin-top: 2px;
line-height: 140%;
*width: 70px;
}
#bsLogoList .bsPromoM {
text-align: center;
}
.bsFooterDiv {
height: 24px;
line-height: 24px;
padding: 0 15px;
border-top: 1px solid #e8e8e8;
background: #f2f2f2;
text-align: right;
}
a.bsLogoLink {
color: #666;
}
.bsLogoLink:hover {
text-decoration: underline;
}
.bsPromoM {
background: url(//static.bshare.cn/frame/images//bshare_box_sprite2.gif) no-repeat top left;
}
.bsNew,
.bsHot,
.bsRec,
.bsAwd {
background-position: 0 -552px;
width: 19px;
margin: 5px auto 1px;
line-height: 16px;
height: 18px;
font-size: 12px;
color: #fff;
overflow: hidden;
}
.bsNew {
background-position: 0 -570px;
}
.bsRec {
width: 30px;
background-position: 0 -588px;
}
.bsAwd {
background: url(//static.bshare.cn/frame/images//promot/promote.gif) no-repeat;
}
</style>
<style type="text/css">
a.bsSiteLink {
text-decoration: none;
color: #666;
}
a.bsSiteLink:hover {
text-decoration: underline;
}
a.bshareDiv {
overflow: hidden;
height: 16px;
line-height: 18px;
font-size: 14px;
color: #333;
padding-left: 0;
}
a.bshareDiv:hover {
text-decoration: none;
}
div.bsTitle {
padding: 0 8px;
border-bottom: 1px solid #e8e8e8;
color: #666;
background: #f2f2f2;
text-align: left;
}
div.buzzButton {
cursor: pointer;
}
div.bsRlogo,
div.bsRlogoSel {
width: 68px;
float: left;
margin: 0;
padding: 2px 0;
}
div.bsRlogo a,
div.bsRlogoSel a {
float: left;
}
div.bsLogo,
div.bsLogoSel {
float: left;
width: 111px;
text-align: left;
height: auto;
padding: 2px 4px;
margin: 2px 0;
white-space: nowrap;
overflow: hidden;
}
div.bsLogoSel,
div.bsRlogoSel {
border: 1px solid #ddd;
background: #f1f1f1;
}
div.bsLogo,
div.bsRlogo {
border: 1px solid #fff;
background: #fff;
}
div.bsLogo a,
div.bsLogoSel a {
display: block;
height: 16px;
line-height: 16px;
padding: 0 0 0 24px;
text-decoration: none;
float: left;
overflow: hidden;
}
div.bsLogoSel a,
div.bsRlogoSel a {
color: #000;
border: none;
}
div.bsLogo a,
div.bsRlogo a {
color: #666;
border: none;
}
div.bsLogoLink {
width: 121px;
overflow: hidden;
background: #FFF;
float: left;
margin: 3px 0;
}
#bsLogin {
float: right;
text-align: right;
overflow: hidden;
height: 100%;
}
#bsPanel {
position: absolute;
z-index: 100000000;
font-size: 12px;
width: 258px;
background: url(//static.bshare.cn/frame/images/background-opaque-dark.png) !important;
padding: 6px !important;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
}
div.bsClear {
clear: both;
height: 0;
line-height: 0;
font-size: 0;
overflow: hidden;
}
div.bsPopupAwd {
background: url(//static.bshare.cn/frame/images//bshare_box_sprite2.gif) no-repeat top left;
background-position: 0 -624px;
width: 18px;
padding-left: 3px;
text-align: center;
float: left;
margin-left: 2px;
height: 15px;
font-size: 12px;
color: #fff;
overflow: hidden;
}
div.bsRlogo .bsPopupAwd,
div.bsRlogoSel .bsPopupAwd {
float: left;
margin: 5px 0 0 -14px;
}
</style>
<script src="//bshare.optimix.asia/bshare_view?Callback=bShare.viewcb&url=http%3A%2F%2Fwww.ruanyifeng.com%2Fblog%2F2009%2F03%2Fcss_selectors.html&h=&uuid=15e016b4-0028-44f1-a40d-a3c9d9c13c28&l=17&lite=1&ref=https%3A%2F%2Fwww.google.com%2F&ot=CSS选择器笔记 - 阮一峰的网络日志&fp=04a88430edb5972e1a73422ff6d7f864&b=bs209d6c" type="text/javascript" charset="utf-8"></script>
<style type="text/css">
a.bsSiteLink {
text-decoration: none;
color: #666;
}
a.bsSiteLink:hover {
text-decoration: underline;
}
a.bshareDiv {
overflow: hidden;
height: 16px;
line-height: 18px;
font-size: 14px;
color: #333;
padding-left: 0;
}
a.bshareDiv:hover {
text-decoration: none;
}
div.bsTitle {
padding: 0 8px;
border-bottom: 1px solid #e8e8e8;
color: #666;
background: #f2f2f2;
text-align: left;
}
div.buzzButton {
cursor: pointer;
}
div.bsRlogo,
div.bsRlogoSel {
width: 68px;
float: left;
margin: 0;
padding: 2px 0;
}
div.bsRlogo a,
div.bsRlogoSel a {
float: left;
}
div.bsLogo,
div.bsLogoSel {
float: left;
width: 111px;
text-align: left;
height: auto;
padding: 2px 4px;
margin: 2px 0;
white-space: nowrap;
overflow: hidden;
}
div.bsLogoSel,
div.bsRlogoSel {
border: 1px solid #ddd;
background: #f1f1f1;
}
div.bsLogo,
div.bsRlogo {
border: 1px solid #fff;
background: #fff;
}
div.bsLogo a,
div.bsLogoSel a {
display: block;
height: 16px;
line-height: 16px;
padding: 0 0 0 24px;
text-decoration: none;
float: left;
overflow: hidden;
}
div.bsLogoSel a,
div.bsRlogoSel a {
color: #000;
border: none;
}
div.bsLogo a,
div.bsRlogo a {
color: #666;
border: none;
}
div.bsLogoLink {
width: 121px;
overflow: hidden;
background: #FFF;
float: left;
margin: 3px 0;
}
#bsLogin {
float: right;
text-align: right;
overflow: hidden;
height: 100%;
}
#bsPanel {
position: absolute;
z-index: 100000000;
font-size: 12px;
width: 258px;
background: url(//static.bshare.cn/frame/images/background-opaque-dark.png) !important;
padding: 6px !important;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
}
div.bsClear {
clear: both;
height: 0;
line-height: 0;
font-size: 0;
overflow: hidden;
}
div.bsPopupAwd {
background: url(//static.bshare.cn/frame/images//bshare_box_sprite2.gif) no-repeat top left;
background-position: 0 -624px;
width: 18px;
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<h1 id="page-title" class="asset-name entry-title">CSS选择器笔记</h1>
<div class="asset-content entry-content" id="main-content">
<p><strong>一、基本选择器</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>1.</td>
<td> <strong>*</strong> </td>
<td> 通用元素选择器，匹配任何元素</td>
</tr>
<tr>
<td>2.</td>
<td> <strong>E</strong></td>
<td> 标签选择器，匹配所有使用E标签的元素</td>
</tr>
<tr>
<td>3.</td>
<td> <strong>.info</strong></td>
<td> class选择器，匹配所有class属性中包含info的元素</td>
</tr>
<tr>
<td>4. </td>
<td><strong>#footer</strong> </td>
<td> id选择器，匹配所有id属性等于footer的元素</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>* { margin:0; padding:0; }</p>
<p>p { font-size:2em; }</p>
<p>.info { background:#ff0; }</p>
<p>p.info { background:#ff0; }</p>
<p>p.info.error { color:#900; font-weight:bold; }</p>
<p>#info { background:#ff0; }</p>
<p>p#info { background:#ff0; }</p>
</div>
</blockquote>
<p><strong>二、多元素的组合选择器</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>5. </td>
<td>E,F</td>
<td> 多元素选择器，同时匹配所有E元素或F元素，E和F之间用逗号分隔</td>
</tr>
<tr>
<td>6. </td>
<td>E F</td>
<td> 后代元素选择器，匹配所有属于E元素后代的F元素，E和F之间用空格分隔</td>
</tr>
<tr>
<td>7.</td>
<td> E > F</td>
<td> 子元素选择器，匹配所有E元素的子元素F</td>
</tr>
<tr>
<td>8.</td>
<td> E + F</td>
<td> 毗邻元素选择器，匹配所有紧随E元素之后的同级元素F</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>div p { color:#f00; }</p>
<p>#nav li { display:inline; }</p>
<p>#nav a { font-weight:bold; }</p>
<p>div > strong { color:#f00; }</p>
<p>p + p { color:#f00; }</p>
</div>
</blockquote>
<p><strong>三、CSS 2.1 属性选择器</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>9. </td>
<td>E[att]</td>
<td> 匹配所有具有att属性的E元素，不考虑它的值。（注意：E在此处可以省略，比如"[cheacked]"。以下同。）</td>
</tr>
<tr>
<td>10.</td>
<td> E[att=val] </td>
<td>匹配所有att属性等于"val"的E元素</td>
</tr>
<tr>
<td>11.</td>
<td> E[att~=val] </td>
<td>匹配所有att属性具有多个空格分隔的值、其中一个值等于"val"的E元素</td>
</tr>
<tr>
<td>12.</td>
<td> E[att|=val] </td>
<td>匹配所有att属性具有多个连字号分隔（hyphen-separated）的值、其中一个值以"val"开头的E元素，主要用于lang属性，比如"en"、"en-us"、"en-gb"等等</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>p[title] { color:#f00; }</p>
<p>div[class=error] { color:#f00; }</p>
<p>td[headers~=col1] { color:#f00; }</p>
<p>p[lang|=en] { color:#f00; }</p>
<p>blockquote[class=quote][cite] { color:#f00; }</p>
</div>
</blockquote>
<p><strong>四、CSS 2.1中的伪类</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>13.</td>
<td> E:first-child </td>
<td>匹配父元素的第一个子元素</td>
</tr>
<tr>
<td>14.</td>
<td> E:link </td>
<td>匹配所有未被点击的链接</td>
</tr>
<tr>
<td>15.</td>
<td> E:visited </td>
<td>匹配所有已被点击的链接</td>
</tr>
<tr>
<td>16.</td>
<td> E:active </td>
<td>匹配鼠标已经其上按下、还没有释放的E元素</td>
</tr>
<tr>
<td>17.</td>
<td> E:hover </td>
<td>匹配鼠标悬停其上的E元素</td>
</tr>
<tr>
<td>18.</td>
<td> E:focus </td>
<td>匹配获得当前焦点的E元素</td>
</tr>
<tr>
<td>19.</td>
<td> E:lang(c) </td>
<td>匹配lang属性等于c的E元素</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>p:first-child { font-style:italic; }</p>
<p>input[type=text]:focus { color:#000; background:#ffe; }</p>
<p>input[type=text]:focus:hover { background:#fff; }</p>
<p>q:lang(sv) { quotes: "\201D" "\201D" "\2019" "\2019"; }</p>
</div>
</blockquote>
<p><strong>五、 CSS 2.1中的伪元素</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>20.</td>
<td> E:first-line</td>
<td> 匹配E元素的第一行</td>
</tr>
<tr>
<td>21. </td>
<td>E:first-letter</td>
<td> 匹配E元素的第一个字母</td>
</tr>
<tr>
<td>22.</td>
<td> E:before</td>
<td> 在E元素之前插入生成的内容</td>
</tr>
<tr>
<td>23.</td>
<td> E:after</td>
<td> 在E元素之后插入生成的内容</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>p:first-line { font-weight:bold; color;#600; }</p>
<p>.preamble:first-letter { font-size:1.5em; font-weight:bold; }</p>
<p>.cbb:before { content:""; display:block; height:17px; width:18px; background:url(top.png) no-repeat 0 0; margin:0 0 0 -18px; }</p>
<p>a:link:after { content: " (" attr(href) ") "; }</p>
</div>
</blockquote>
<p><strong>六、CSS 3的同级元素通用选择器</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>24.</td>
<td> E ~ F </td>
<td>匹配任何在E元素之后的同级F元素</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>p ~ ul { background:#ff0; }</p>
</div>
</blockquote>
<p><strong>七、CSS 3 属性选择器</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>
<td>序号</td>
<td>选择器</td>
<td>含义</td>
</tr>
<tr>
<td>25.</td>
<td> E[att^="val"] </td>
<td>属性att的值以"val"开头的元素</td>
</tr>
<tr>
<td>26.</td>
<td> E[att$="val"] </td>
<td>属性att的值以"val"结尾的元素</td>
</tr>
<tr>
<td>27.</td>
<td> E[att*="val"] </td>
<td>属性att的值包含"val"字符串的元素</td>
</tr>
</tbody>
</table>
<p>实例：</p>
<blockquote>
<div>
<p>div[id^="nav"] { background:#ff0; }</p>
</div>
</blockquote>
<p><strong>八、CSS 3中与用户界面有关的伪类</strong></p>
<table border="1" style="width:500px;text-align:center;">
<tbody>
<tr>