偶数个和奇数个li标签单独设置样式

.center_top_right ul li:nth-child(odd){   //奇数
    list-style: none;
    width: 90px;
    height: 70px;
    float: right;
}
.center_top_right ul li:nth-child(even){   //偶数
    list-style: none;
    width: 10px;
    height: 70px;
    color: #666;  
    float: right;
}