纯CSS弹出层的示例代码

<html>
<head>
	<style>
		.bluequestionmark
		{
    		background-repeat:no-repeat;
    		display:inline-block;
    		background-size:16px 16px;
    		16px;
    		height:16px;
    		position:relative;/*the out div must be position:relative*/
		}

		a.tipinfo
		{
    		display:none;
		}

		div.bluequestionmark:hover a.tipinfo
		{
    		white-space:nowrap;/*the pop up infomation will show in one line*/
    		display:block;
    		border:1px solid #0094ff;
   			position:absolute;
    		top:18px;
    		left:0px;
    		padding:6px 10px;
    		background-color:white;
		}

		a.tipinfo:hover a.tipinfo
		{
    		white-space:nowrap;
    		display:block;
    		border:1px solid #0094ff;
   			position:absolute;
    		top:18px;
    		left:0px;
    		padding:6px 10px;
    		background-color:white;
    		cursor: text;
		}
	</style>
</head>
<body>
	move your mouse to pic
	<div class="bluequestionmark" style="background-image:url('http://img.blog.csdn.net/20131206112028640')">
        <a class="tipinfo">a lot of pop up information</a>
    </div>
</body>
</html>

原文地址:https://www.cnblogs.com/rav009/p/5131095.html