聖杯レイアウトと両翼レイアウト_html/css_WEB-ITnose

<div class="wrap">  <div class="main">    我是主要  </div>  <div class="left">    我是左边  </div>  <div class="right">    我是右边  </div></div>

* {    margin: 0;    padding: 0}.main {    background-color: yellow;    height: 100px;    float: left;    width: 100%;}.left {    background-color: red;    width: 200px;    height: 100px;    float: left;     margin-left: -100%; /*margin负边距*/    position: relative; /*相对自身偏移*/    left: -200px; }.right {    background-color: blue;    width: 200px;    height: 100px;    float: left;    margin-left: -200px; /*margin负边距*/    position: relative;  /*相对自身偏移*/    right: -200px;   }.wrap {    padding: 0 200px;  /*父级设置padding*/}