/* 居中 */
#header, #content, #footer {
    margin-left: auto;
    margin-right: auto;
}

/** 布局基础样式 **/
.col-main {
    float: left;
    width: 100%;
    /* bug fix: 主栏没有内容时，在 Firefox 和 Chrome 等浏览器下，布局不对 */
    min-height: 1px;
}
.col-sub, .col-extra {
    float: left;
    /*position: relative;  按需设置，仅在需要时添加 */
}

/** 清除浮动 **/
.layout:after, .main-wrap:after, .col-sub:after, .col-extra:after {
	content: '\20';
	display: block;
	height: 0;
	clear: both;
}
.layout, .main-wrap, .col-sub, .col-extra {
    *zoom: 1;
}

/*
淘宝采用了 6 种栅格布局：
950                  .grid-m
190    750           .grid-s5m0
750    190           .grid-m0s5
190    510    230    .grid-s5m0e6
230    510    190    .grid-e6m0s5
510    230    190    .grid-m0e6s5
*/

/** 两栏布局 **/
.grid-s5m0 .main-wrap { margin-left: 200px; }
.grid-s5m0 .col-sub { width: 190px; margin-left: -100%; }

.grid-m0s5 .main-wrap { margin-right: 200px; }
.grid-m0s5 .col-sub { width: 190px; margin-left: -190px; }

.grid-m0s6 .main-wrap { margin-right: 250px; }
.grid-m0s6 .col-sub { width: 240px; margin-left: -240px; }

/** 三栏布局 **/
.grid-s5m0e6 .main-wrap { margin: 0 240px 0 200px; }
.grid-s5m0e6 .col-sub { width: 190px; margin-left: -100%; }
.grid-s5m0e6 .col-extra { width: 230px; margin-left: -230px; }

.grid-e6m0s5 .main-wrap { margin: 0 200px 0 240px; }
.grid-e6m0s5 .col-sub { width: 190px; margin-left: -190px; }
.grid-e6m0s5 .col-extra { width: 230px; margin-left: -100%; }

.grid-m0e6s5 .main-wrap { margin-right: 440px; }
.grid-m0e6s5 .col-sub { width: 190px; margin-left: -190px; }
.grid-m0e6s5 .col-extra { width: 230px; margin-left: -430px; }

/** 页面宽度 **/
.w960 #header, .w960 #content, .w960 #footer{ width:960px;background:#fff;}