<div></div>
div{
height: 48px;
width: 80px;
padding: 0 16px 0 32px;
background: rgba(0,0,0,.6);
position: relative;
overflow: hidden;
}
div:after{
display: block;
content: "";
height: 24px;
width: 24px;
position: absolute;
top: 12px;
right: -12px;
background: #FFFFFF;
border-radius: 50%;
}
css完成下图
原文地址：https://www.cnblogs.com/namehou/p/10457352.html