CSS 实例：为页面规定默认文本字体 - 在线编辑器

          <html>
<head>
  <style>
    body {
      font-size: 50px;
    }
  </style>
</head>
<body>

  <h1>This is a header (headers are not affected by the font-size property)</h1>
  <p>This is a paragraph.</p>

</body>
</html>
        