trycss_sel_attribute_hyphen 在线代码实例

 <h1 class="top-header">Welcome</h1>
<p class="top-text">Hello world!</p>
<p class="content">Are you learning CSS?</p>

<p><b>Note:</b> For [<i>attribute</i>|=<i>value</i>] to work in IE8 and earlier, a DOCTYPE must be declared.</p>