属性选择器

根据不同标签的来选择自己所需要的

<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
		<!--dem下的a   -->
        .demo a{
            float:left;/*向左浮动*/
            display:block;
            height: 50px;
            width: 50px;
            border-radius: 10px;
            background: green;
            text-align: center;/*文字居中*/
            color: gainsboro;/*文字颜色*/
            margin-right: 5px;
            font: bold 20px/50px Arial;
        }
        /* 存在id的元素*/
        a[id]{
            background: blueviolet;
        }

        /*class为links的变色*/
        a[class*="links"]{
            background: aqua;
        }

        /*选中herf中以HTTP开头的元素*/
        a[href^=http]{
            background: yellow;
        }
        /*选中以pdf结尾的*/
        a[href$=pdf]{
            background: pink;
        }
    </style>
</head>
<body>
<p class="demo">
    <a href="http://www.baidu.com" class="links item frist" id="frist">1</a>
    <a href="" class="links item active" target="_blank" title="test">2</a>
    <a href="images/123.html" class="links item">3</a>
    <a href="images/123.png" class="links item">4</a>
    <a href="images/123.jpg" class="links item">5</a>
    <a href="abc" class="links item">6</a>
    <a href="/a.pdf" class="links item">7</a>
    <a href="/abc.doc" class="links item">8</a>
    <a href="abc.doc" class="links item">9</a>
    <a href="dac.doc" class="links item last">10</a>
</p>

</body>