* {
    margin: 0;
    padding: 0;
}

li {
    list-style: none;
}

a {
    text-decoration: none;
}

.w {
    width: 1200px;
    margin:auto;
}
.banner {
    background: url(qtzpzq_banner20230610.png) no-repeat top center;
    background-size: cover;
    width: 100%;
    height: 400px;
}

.banner img {
    width: 370px;
    position: absolute;
    left: 50px;
    top: 20px;
    z-index: 2;
}

.center ul li {
    float: left;
    width: 550px;
    height: 260px;
    margin-left: 20px;
    margin-top: 20px;

}

.center ul li img {
    width: 100%;
    height: 100%;
}

@media screen and (max-width: 769px) {
    .banner {
        background: url(qtzpzq_banner20230610.png) no-repeat top center;
        background-size: cover;
        width: 100%;
        min-width: 1200px;

    }
}