w3school TIY
编辑您的代码：
<!DOCTYPE HTML> <html> <body> <h1>This is header 1</h1> <h2>This is header 2</h2> <h3>This is header 3</h3> <h4>This is header 4</h4> <h5>This is header 5</h5> <h6>This is header 6</h6> </body> </html>
查看结果: