margin测试.html

<head>
	<style type="text/css">
		.f1{
			background: #000;
			width: 300px;
			height: 400px;
			position: absolute;
			top:200px;
		}
		.c1{
			float: left;
			background: green;
			height: 300px;
			width:100px;
			margin-right: -200px;
		}
		.c2{
			float:right;
			background: red;
			width: 200px;
			/*不设置width,margin负值会增加width*/
			height: 200px;
			/*margin-right: -40px;*/
			margin-top: -100px;
			/*margin-bottom: -100px;*/
		}
	</style>
</head>

<body>
	<div class='f1'>
		<div class='c1'></div>
		<div class='c2'>
		</div>
	</div>
</body>