css完成下图

<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%;

}