html {
    box-sizing: border-box;
    -webkit-scroll-behavior: smooth;
    -moz-scroll-behavior: smooth;
    -ms-scroll-behavior: smooth;
    scroll-behavior: smooth;
}

body {
    margin: 0;
}

a {
    -webkit-text-decoration: none;
    text-decoration: none;
}

p {
    margin: 0;
}

*,
*:before,
*:after {
    box-sizing: inherit;
}

* {
    -webkit-font-smoothing: antialiased;
}
body {
    margin: 0;
    padding: 0;
    background-color: white;
    font-family: "Microsoft YaHei";
}

.container {
    position: relative;
    max-width: 750px;
    min-width: 300px;
    margin: 0 auto;
}
.container .background {
    max-width: 100%;
    font-size: 0;
    line-height: 0;
    vertical-align: top;
    margin-top: -0.9px;
}
.container .piece-column {
    position: relative;
    line-height: 0;
    font-size: 0;
}
.container .download {
    position: absolute;
    left: 8%;
    right: 8%;
    height: 6rem;
}
.container .nav-btn {
    top: 0;
    right: 0;
    left: 50%;
}

.container .down-btn03 {
    bottom: 0%;
    height: 8rem;
}