<html><head><title>This is the title</title><style>
h1{#元素选择器
color:red;#定义前景色
background-color:yellow;}#content{ #id选择器
color:black:
background-color:white;}
.content{#类选择器
color:blue;
background-color:green;
font-size:16px;}
a[href]{#属性选择器
color:darkbule;
font-size:23px;}
h2 em{#后代选择器
color:oldlace;}
h3 >l{#子元素选择器
color:orange;
border:green solid 1px;#dashed为实心边框}
li + p{#相邻兄弟选择器
font-weight:bold;
outline:greenyellow dotted 5px;#轮廓}</style></head><body><h1>This is the content</h1><h2 id="content">This is the another content</h1><h2 class="content">This is the another content</h1><a href>This is the another content</a><h2><em>still a content</em></h2><h3>Again <em>is </em>a <l>the </l>content</h3><ul><li>Last a the content</li><p>Last a the content</p><li>Lat a the content</li><p>Last a the content</p></ul><p>Last a the content</p></body></html>
