/*设置图片尺寸一样高的*/
.bigimg {
    width: 100%;
    height: 300px;
    overflow: hidden;
    position: relative;
}
.bigimg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}



@media (max-width: 1000px) {
    .bigimg {
        height: 240px;
    }

}
@media (max-width: 770px) {
    .bigimg {
        height: 150px;
    }


}