CSS学习遇到问题,注释问题
<!DOCTYPE HTML>
<head>
<style type="text/css">
<!--h1em{color:red}-->
ul em{color:red;font-weight:bold}
h1 > strong {color:red}
</style>
</head>
显示
<head>
<style type="text/css">
<!--h1 em{color:red}-->
ul em{color:red;font-weight:bold}
h1 > strong {color:red}
</style>
</head>
显示
有空格和没有空格有区别