有人可以解释为什么section计数器值在所有h2标签中都打印0 ？
这是源代码:
<!DOCTYPE html>
<html>
<head>
<style>
body {
counter-reset: section;
counter-reset: subsection;
}
h1::before {
counter-increment: section;
content: "Section " counter(section) ". ";
}
h2::before {
counter-increment: subsection;
content: counter(section) "." counter(subsection) " ";
}
</style>
</head>
<body>
<h1>HTML tutorials:</h1>
<h2>HTML Tutorial</h2>
<h2>CSS Tutorial</h2>
<h1>Scripting tutorials:</h1>
<h2>JavaScript</h2>
<h2>VBScript</h2>
<h1>XML tutorials:</h1>
<h2>XML</h2>
<h2>XSL</h2>
<p><b>Note:</b> IE8 supports these properties only if a !DOCTYPE is specified.</p>
</body>
</html>css ×1