以下实例演示了如何在提示工具的头部添加箭头，注意设置边框颜色 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
</head>
<style>
  .tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted black;
  }

  .tooltip .tooltiptext {
    visibility: hidden;
    width: 120px;
    background-color: black;
    color: #fff;
    text-align: center;
    border-radius: 6px;
    padding: 5px 0;
    position: absolute;
    z-index: 1;
    top: 150%;
    left: 50%;
    margin-left: -60px;
  }

  .tooltip .tooltiptext::after {
    content: "";
    position: absolute;
    bottom: 100%;
    left: 50%;
    margin-left: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: transparent transparent black transparent;
  }

  .tooltip:hover .tooltiptext {
    visibility: visible;
  }
</style>
<body style="text-align:center;">

  <h2>底部提示框/顶部箭头</h2>

  <div class="tooltip">鼠标移动到我这
    <span class="tooltiptext">提示文本</span>
  </div>

</body>
</html>
        