//圣杯布局-wrap设置padding/left right加相对定位
<!DOCTYPE html>
<html lang="zh-CN">
<html>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
<title></title><style>*{margin:0; padding:0;}.wrap{padding:0 200px; overflow: hidden}.main{width:100%; background:#57ccb1; float:left; height:100px;}.left{ float:left;margin-left:-100%; width:200px; height:100px; background:#ff3f27; position:relative; left:-200px;}.right{ float:left;margin-left:-200px; width:200px; height:100px; background:#fbb800; position:relative;right:-200px;}</style>
</head>
<body><div class="wrap"><div class="main">main</div><div class="left">left</div><div class="right">right</div>
</div></body>
</html>
//双飞翼布局-在main中嵌套一层设置margin
<!DOCTYPE html>
<html lang="zh-CN">
<html>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
<title></title><style>*{margin:0; padding:0;}.main{width:100%; background:#57ccb1; float:left; height:100px;}.left{ float:left;margin-left:-100%;opacity:0.4; width:200px; height:100px; background:#ff3f27; }.right{ float:left;margin-left:-200px;opacity:0.4; width:200px; height:100px; background:#fbb800; }.main_con{margin-left:200px; margin-right:200px;}</style>
</head>
<body><div class="wrap"><div class="main"><div class="main_con">main</div></div><div class="left">left</div><div class="right">right</div>
</div></body>
</html>
