* {
    padding: 0;
    margin: 0;
}

img {
    width: 100%;
    max-width: 100%;
}
.topimg{
    position: fixed;
    left: 15px;
    right: 15px;
    top: 15px;
}
.contentbox {
    background-color: #000;
    padding: 100px 15px 20px 15px;
}
.bottomimg{
    position: fixed;
    left: 15px;
    right: 15px;
    bottom: 5px;
}
.online_btn{
    position: absolute;
    width: 110px;
    height: 50px;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
}
.thin_btn{
    position: absolute;
    width: 110px;
    height: 50px;
    left: 50%;
    display: none;
    top: 50%;
    transform: translate(-50%,-50%);
    display: none;
}
.download_btn{
    position: absolute;
    width: 110px;
    height: 50px;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 99;
}

#iosimg{
    display: none;
}