html,
head,
body,
div,
p,
button,
h3 {
    padding: 0;
    margin: 0 auto;
    font-family: 微软雅黑;
}

body {
    min-width: 320px;
    max-width: 720px;
    max-height: 1280px;
    height: 100%;
    font: normal 100% 微软雅黑, Helvetica, Arial, sans-serif;
    color: #000;
}

#top {
    width: 100%;
    height: 10%;
    border-bottom: 1px solid #ddd;
    position: relative;
    z-index: 0;
}


#top img {
    width: 27%;
    height: auto;
    margin: 2% 0 1% 4%;
}

#top .adv {
    font-size: 1em;
    color: #404040;
    float: right;
    position: absolute;
    bottom: 20%;
    right: 5%;
}

#download_content {
    text-align: center;
}

#download_content h3 {
    font-size: 1.8em;
    margin-top: 10%;
    font-weight: 300;
}

#download_content p {
    font-size: 1.2em;
    margin-top: 2%;
    line-height: 1.8em;
    color: #404040;
}

.download_icon img {
    margin: 6% auto 10% auto;
    width: 20%;
    min-width: 100px;
    height: auto
}

button {
    border: none;
    width: 70%;
    height: 2em;
    border-radius: 2em;
    background-color: #009afa;
    color: #fff;
    font-size: 1.5em;
    cursor: pointer;
}

button:focus {
    border: none;
    outline: none;
}

button:active {
    box-shadow: 0 0 4px #009afa;
    border: none;
    outline: none;
}

.wechat_tip_wrap {
    width: 100%;
    height: 100%;
    position: absolute;
    background-color: rgba(0,0,0,.6);
    display: none;
    z-index: 11;
}

.wechat_tip {
    width: 320px;
    height: 192px;
    position: absolute;
    right: calc(50% - 160px);
    top: 30px;
}