为什么我这一段代码不生效
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文网(php.cn)</title>
<style>
#11
{
text-align:center;
color:red;
}
</style>
</head>
<body>
<p id="11">php中文网(php.cn)</p>
<p>这一段不受css样式影响。</p>
</body>
</html><!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文网(php.cn)</title>
<style>
#11
{
text-align:center;
color:red;
}
</style>
</head>
<body>
<p id="11">php中文网(php.cn)</p>
<p>这一段不受css样式影响。</p>
</body>
</html>
