@media screen and (max-width:420px) {
    .waikuang{
        height: 220px !important;
    }
    .waikuang img{
        margin: 20px auto;
        width: 95% !important;
    }
    .bjianimg{
        width: 100%;
    }
}

@media screen and (max-width:992px) {
    .nwnzsmm{
        margin-top: 100px;
    }
    .zw_1{
        margin-top: 20px;
        max-width: 650px;
    }
    .bt_1{
        max-width: 650px;
        margin-top: 40px;
    }
}

@media screen and (min-width:993px) {
    .nwnzsmm{
        margin-top: 40px;
    }
    .zw_1{
        margin-top: 20px;
        /*max-width: 650px;*/
    }
    .bt_1{
        /*max-width: 650px;*/
        margin-top: 40px;
    }
}
.nwnzsm{
    margin-top: 60px;
}
.waikuang{
    width: 100%;  
    height: 250px;
    border: 1px solid #ccc; 
    border-radius: 10px;
    transition: all 0.5s ease;
    margin: 0 0 40px 0;
}
.waikuang img{
    margin: 20px auto;
}
.waikuang:hover{
    /*margin-top: -10px;*/
    box-shadow: 0px 16px 30px #00000040;
}
.nwnzsm_2{
    margin-bottom: 20px;
}