/* 保持参考页面的全宽、无间隔图片展示。 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: "Microsoft YaHei", Arial, sans-serif;
    color: #1b2b45;
    background: #fff;
}
img {
    width: 100%;
    display: block;
    object-fit: cover;
}
.banner {
    width: 100%;
    overflow: hidden;
    display: flex;
    justify-content: center;
}
.banner picture,
.banner img {
    width: 100%;
}
.banner img {
    height: auto;
}