console 命令行工具 X clear
console
<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <title>Page Not Found</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <style>
    html {
      color: #888;
      display: table;
      font-family: sans-serif;
      height: 100%;
      text-align: center;
      width: 100%;
    }

    body {
      display: table-cell;
      vertical-align: middle;
      margin: 2em auto;
    }

    h1 {
      color: #555;
      font-size: 2em;
      font-weight: 400;
    }

    p {
      margin: 0 auto;
      width: 280px;
    }

  </style>
</head>

<body>
  fadsfsdfdsfd
</body>

</html>