body {
    background-image: url("https://webstatic.mihoyo.com/upload/static-resource/2021/11/08/55ccd259cca4f64ae81f2d113a153bae_8366165624319984079.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    justify-content: center;
    height: auto;
}
.boxx{
    background-color: rgba(0, 0, 0, 0.8); /* 半透明的黑色背景 */
    border-radius: 10px; /* 圆角边框 */
    width: 800px;
    height: 800px;
    margin: 0 auto;
}