定制TAB样式，纯CSS实现

<!DOCTYPE HTML>
<html>
<head>
    <meta charset="utf-8">
    <title>42度空间-定制TAB样式，纯CSS实现</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .tabs {
            margin:1rem;
            max-width: 100%;
            min-width: 320px;
        }
        .tabs input {
            height: 2.5em;
            visibility: hidden;
        }
        .tabs label {
            background: #f9f9f9;
            border-radius: .25em .25em 0 0;
            color: #888;
            cursor: pointer;
            display: block;
            float: left;
            font-size: 1em;
            height: 2.5em;
            line-height: 2.5em;
            margin-right: .25em;
            padding: 0 1.5em;
            text-align: center;
        }
        .tabs input:hover + label {
            background: #ddd;
            color: #666;
        }
        .tabs input:checked + label {
            background: #f1f1f1;
            color: #444;
            position: relative;
            z-index: 6;
        }
        .content {
            background: #f1f1f1;
            border-radius: 0 .25em .25em .25em;
            min-height: 120px;
            position: relative;
            width: 100%;
            z-index: 5;
        }
        .content div {
            opacity: 0;
            padding: 1.5em;
            position: absolute;
            z-index: -100;
        }
        .content p {
            clear: both;
            padding-bottom: 2rem;
        }
        .tabs input#tab-1:checked ~ .content #content-1,
        .tabs input#tab-2:checked ~ .content #content-2,
        .tabs input#tab-3:checked ~ .content #content-3 {
            opacity: 1;
            z-index: 100;
        }
        input.visible {
            visibility: visible !important;
        }
    </style>
</head>
<body>
<div class="tabs">
    <input id="tab-1" type="radio" name="tab-group" checked="checked" />
    <label for="tab-1">知 识</label>
    <input id="tab-2" type="radio" name="tab-group" />
    <label for="tab-2">名 言</label>
    <input id="tab-3" type="radio" name="tab-group" />
    <label for="tab-3">笑 话</label>
    <div class="content">
        <div id="content-1">
            <p>
                在JavaScript中，永远不要用for in循环来遍历数组。
            </p>
        </div>
        <div id="content-2">
            简单是稳定的前提。 
        </div>
        <div id="content-3">
            程序员最讨厌的四件事：写注释、写文档、别人不写注释、别人不写文档。
        </div>
    </div>
</div>
</body>
</html>