<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
.assistive-wrap{
width: 58px;
height: 58px;
position: fixed;
top: 50%;
margin-top: -29px;
left: 1px;
}
.assistive-touch{
width: 100%;
height: 100%;
background: #343434;
border-radius: 10px;
opacity: .3;
position: relative;
}
.assistive-touch:before, .assistive-touch:after, .assistive-touch span{
content: ‘‘;
position: absolute;
border-radius: 100%;
box-shadow: 0 0 2px rgba(30, 30, 30, .5);
display: block;
background: rgba(255, 255, 255, .6);
}
.assistive-touch:before{
width: 42px;
height: 42px;
left: 8px;
top: 8px;
opacity: .5;
}
.assistive-touch span{
width: 34px;
height: 34px;
left: 12px;
top: 12px;
}
.assistive-touch:after{
width: 26px;
height: 26px;
left: 16px;
top: 16px;
background: #fff;
}
</style>
</head>
<body>
<div class="assistive-wrap">
<div class="assistive-touch">
<span></span>
</div>
</div>
</body>
</html>
Html - 仿Ios assistiveTouch 悬浮辅助球工具
原文：http://www.cnblogs.com/CyLee/p/5324357.html