css三栏布局:1.中自:float,absolute,margin三种方法.2.中固:margin,table两种方法. 两边定宽,中间自适应: float: #left{ float:left; width:220px; height:200px; background-color: red; } #right{ float:right; width:220px; height:200px; background-color: red; } #main{ margin:0 230px; he…