右侧提示框/左侧箭头：
.tooltip .tooltiptext::after {
content: " ";
position: absolute;
top: 50%;
right: 100%; /* 提示工具左侧 */
margin-top: -5px;
border-width: 5px;
border-style: solid;
border-color: transparent black transparent transparent;
}
https://www.lekaowang.com/bim/nqw/tvv/ 标签：右侧,箭头,左侧,提示框,border,transparent From： https://www.cnblogs.com/5-si6/p/17295884.html