关于background的用法
.box{
width:1200px;
margin:auto;
background:#C90;
}
.ul{
overflow:hidden;
}
.li{
width:380px;
height:300px;
margin-right:20px;
background:green;
float:left;
}
</style>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<body>
<div class="box">
<div calss="ul">
<div class="li">1</div>
<div class="li">2</div>
<div class="li">3</div>
</div>
</div>
为什么<div class="box"></div>的背景色显示不出来？
