css写圆角效果

.introTips i{
    position: absolute;
    display: block;
    top: 8px;
    right: 8px;
    width: 0;
    height: 0;
    font-size: 0;
    line-height: 0;
    border-top: 5px solid #fff;
    border-right: 3px solid transparent;
    border-left: 3px solid transparent;
}