以下代码都可直接复制使用看效果
普通提示框

先看效果：
动画.gif
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div>
      <div class="wrapper">
        I have a tooltip.
        <div class="tooltip">I am a tooltip!</div>
      </div>
    </div>
    <style>
      .wrapper {
        text-transform: uppercase;
        background: #ececec;
        color: #555;
        cursor: help;
        font-family: "Gill Sans", Impact, sans-serif;
        font-size: 20px;
        margin: 100px 75px 10px 75px;
        padding: 15px 20px;
        position: relative;
        text-align: center;
        width: 200px;
        -webkit-transform: translateZ(0); /* webkit flicker fix */
        -webkit-font-smoothing: antialiased; /* webkit text rendering fix */
      }

      .wrapper .tooltip {
        background: #1496bb;
        bottom: 100%;
        color: #fff;
        display: block;
        left: -25px;
        margin-bottom: 15px;
        opacity: 0;
        padding: 20px;
        pointer-events: none;
        position: absolute;
        width: 100%;
        -webkit-transform: translateY(10px);
        -moz-transform: translateY(10px);
        -ms-transform: translateY(10px);
        -o-transform: translateY(10px);
        transform: translateY(10px);
        -webkit-transition: all 0.25s ease-out;
        -moz-transition: all 0.25s ease-out;
        -ms-transition: all 0.25s ease-out;
        -o-transition: all 0.25s ease-out;
        transition: all 0.25s ease-out;
        -webkit-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
        -moz-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
        -ms-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
        -o-box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
        box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.28);
      }

      /* 弥补提示框和元素之间的空白 */
      .wrapper .tooltip:before {
        bottom: -20px;
        content: " ";
        display: block;
        height: 20px;
        left: 0;
        position: absolute;
        width: 100%;
      }

      /* 提示框下的小三角 */
      .wrapper .tooltip:after {
        border-left: solid transparent 10px;
        border-right: solid transparent 10px;
        border-top: solid #1496bb 10px;
        bottom: -10px;
        content: " ";
        height: 0;
        left: 50%;
        margin-left: -13px;
        position: absolute;
        width: 0;
      }

      .wrapper:hover .tooltip {
        opacity: 1;
        pointer-events: auto;
        -webkit-transform: translateY(0px);
        -moz-transform: translateY(0px);
        -ms-transform: translateY(0px);
        -o-transform: translateY(0px);
        transform: translateY(0px);
      }

      /* IE只能显示隐藏 无法过渡 */
      .lte8 .wrapper .tooltip {
        display: none;
      }

      .lte8 .wrapper:hover .tooltip {
        display: block;
      }
    </style>
  </body>
</html>
纯css实现提示框

普通提示框
