* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html, body {
    width: 100%;
    background-color: black;
}
.banner-container {
    width: 100%;
    padding-top: 56.25%; /* 16:9 aspect ratio */
    background-image: url('../img/banner.png'); /* 请替换为实际的banner图片路径 */
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
    position: relative;
}