* {
    margin: 0;
}

html {
    font-size: calc(100vw / 7.5);
    /* 默认使用动态 rem 计算 */
}

/* 当屏幕宽度 >= 750px 时，固定 rem 字号为设计稿对应的基准值 */
/* 假设你的设计稿是以 750px 宽度为基础，1rem = 100px */
/* @media screen and (min-width: 750px) {
    html {
        font-size: 100px;
    }
} */

.wrap {
    width: 100%;
    max-width: 750px;
    min-height: 100vh;
    background: url('../image/bg.jpg') top center no-repeat;
    background-size: cover;
    margin: 0 auto;
}

.wrap .header {
    position: relative;
}

.wrap .header .banner {
    width: 45%;
    margin: 0 auto;
    display: block;
}

.wrap .header .kefu {
    position: absolute;
    top: 0.3rem;
    right: 0.15rem;
    width: 1rem;
}

.wrap .title img {
    width: 90%;
    display: block;
    margin: 0 auto;
    margin-top: -1rem;
    margin-left: 0.5rem;
}

.wrap .describe img {
    width: 100%;
    display: block;
    margin: 0 auto;
    margin-top: 0.2rem;
}

.wrap .content img {
    width: 90%;
    display: block;
    margin: 0 auto;
    margin-top: 0.3rem;
}

.wrap .btnGroup {
    width: 100%;
    margin-top: 0.5rem;
}

.wrap .btnGroup {
    width: 100%;
    margin-top: 0.5rem;
}

.wrap .btnGroup .download {
    width: 80%;
    display: block;
    margin: 0 auto;
}

.wrap .btnGroup .visitUS {
    width: 55%;
    display: block;
    margin: 0 auto;
    margin-top: 0.2rem;
}

.wrap .footer {
    height: 5.85rem;
}