flex容器内嵌iframe框架居中显示操作。代码更简便

  <body>
    <style>
      .flex-container {
        display: flex;
        width: auto;
        height: 37.2em;
        border: 1px solid;
        background-color: lightblue;
        place-content: space-evenly;
      }
    </style>
    <div class="flex-container">
      <iframe
        src="http://wwww2.com/app/index.php?c=entry&i=1&do=index&m=gf_qddh5"
        id="shequn"
      ></iframe>
    </div>
  </body>