/* 顶部header 宽度 */
@media (min-width: 700px){
    header .left{
        width: 200px;
        text-align: center;
    }
    
    header .middle{
        width: 340px;
    }

    header .right{
        width: 160px;
    }
}

@media (min-width: 900px){
    header .left{
        width: 200px;
        text-align: center;
    }
    
    header .middle{
        width: 480px;
    }

    header .right{
        width: 240px;
    }
}

@media (min-width: 1100px){
    header .left{
        width: 180px;
        text-align: center;
    }
    
    header .middle{
        width: 640px;
    }

    header .right{
        width: 280px;
    }
}

@media (min-width: 1400px){
    header .left{
        width: 200px;
        text-align: center;
    }
    
    header .middle{
        width: 900px;
    }

    header .right{
        width: 300px;
    }
}