.danjian_topBg {
    background: url(../images/danjianbg.jpg) no-repeat center;
    min-height: 150px;
    display: flex;
    align-items: center;
}

.danjian {
    margin: 0px auto;
    text-align: center;
}

.danjian_topBg img {
    max-width: 100%;
}

@media (max-width:550px) {
    .danjian_topBg {
        background-size: cover;
        min-height: 80px;
    }
}