.banner-img{ width: 100%;border-bottom: 2px #eee solid; height: 450px;}
.banner-img img{ width: 100%;height: 450px;}
.neirong-content{ min-height:800px; max-width: 1000px; margin: 0 auto;}

.content-nav{background-color: #eee;width:280px; float: right;min-height:800px;}
.content-list{background-color: #eee; float: left;width: calc(100% - 300px);min-height:800px; }