css 伪元素方法写小圆点

.icon-size-12 {
    cursor: pointer;
    width: 16px;
    height: 16px;
    margin: 22px 30px 0 0;
    background-position: center;
    background-repeat: no-repeat;
    float: right;
    //小圆点
    &.unread {
        position: relative;
        &:after {
            content: ' ';
            position: absolute;
            right: -4px;
            top: -2px;
            width: 8px;
            height: 8px;
            background-color: red;
            border-radius: 4px;
        }
    }

}