悬浮按钮

 1.css样式 :

<style>
#topBtn {
    position: fixed;
    bottom: 380px;
    right: 50px;
    width: 60px;
    height: 60px;
    line-height: 60px;
    text-align: center;
    color: #FFF;
    z-index: 999;
    background: #FF5722;
    cursor: pointer;
    border-radius: 30px;
    box-shadow: 0px 0px 20px #000;
}
</style>

 3.html 代码:

 <div id="topBtn">置顶</div>