* {
    box-sizing: border-box;
}

body {
    margin: 0 auto;
}

#wrapper {
    display: flex;
    flex-direction: column;
    background-color: #1E4DFF;
    width: 100%;
    min-height: 100%;
    overflow-x: hidden;
}

header {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem 1rem;
    background-color: #333333;
}
    
div #wx {
    color: #FFFFFF;
    font-size: 1.2rem;
    text-align: center;
}

main {
    /*垂直佈局*/
    display: flex;
    flex-direction: column;
}

div #logo {
    display: flex;
    justify-content: center;
}

div #logo img {
    margin-top: 8rem;
    /*width: 276px;*/
    /*height: 94px;*/
}

div #subtitle {
    margin-top: 2rem;
    color: #FFFACC;
    font-size: 48px;

    display: flex;
    justify-content: center;
    align-items: center;
}

div #download {
    margin-top: 4rem;

    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

div #download div {
    flex-shrink: 0;
    align-self: center;
    width: 300px;
    height: 400px;
    background-color: white;
    border-radius: 10px;
    margin: 0 2rem 4rem;
}

.img_dl_qr {
    width: 180px;
    height: 180px;
    margin: 60px 60px 50px;
}

.img_dl {
    width: 260px;
    height: 74px;
    margin: 0 20px;
}

footer {
    flex: 0;
    color: #B4B4B5;
    background-color: white;
    text-align: center;
    font-size: 1rem;
    line-height: 8px;
}

footer a:link {
    color: #B4B4B5;
}

footer a:visited {
    color: #B4B4B5;
}

@media (max-width: 640px) {
    div #logo img {
        margin-top: 4rem;
        /*width: 226px;*/
        /*height: 79px;*/
    }

    div #subtitle {
        margin-top: 18px;
        color: #FFFACC;
        font-size: 28px;
    }
    
    div #download {
        margin-top: 3rem;
    }

    div #download div {
        width: 240px;
        height: 320px;
        margin-bottom: 3rem;;
    }

    .img_dl_qr {
        width: 144px;
        height: 144px;
        margin: 48px 48px 40px;
    }

    .img_dl {
        width: 208px;
        height: 58px;
        margin: 0 16px;
    }

    footer {
        font-size: 0.9rem;
        text-overflow: ellipsis;
        white-space: nowrap;
        padding-top: 0.5rem;
        padding-bottom: 1rem;
    }
}