* {
    margin: 0;
    padding: 0;
    -webkit-user-drag: none;
} 

.wrap {
    margin: 0 auto;
    width: 6.4rem;
    height: 16rem;
    max-width: 640px;
    /* max-height: 1600px; */
    overflow-x: hidden;
    background: url("../img/bg.jpg") no-repeat;
    background-size: 100% auto;
    position: relative; /* 父容器使用相对定位 */
}

.btn_pos {
    width: 3.06rem;
    height: 0.9rem;
    animation: myBreath 1s linear infinite;
    position: relative; /* 子元素相对于父容器定位 */
    left: 1.67rem;
    top: 8rem;
}

@keyframes myBreath {
  0% {
    transform: scale(0.88);
  }
  50% {
    transform: scale(100%);
  }
  100% {
    transform: scale(0.88);
  }
}

.btn_up {
    width: 100%;
    height: 100%;
    display: block;
}

.footer {
    position: fixed;
    bottom: 0;
    width: 6.4rem;
    height: 1rem;
    background-color: #fff;
}

.footer .icon {
    width: 0.8rem;
    height: 0.8rem;
    border-radius: 0.1rem;
    position: absolute;
    left: 0.2rem;
    top: 0.1rem;
}

.footer .desc {
    width: 3.2rem;
    height: 1rem;
    position: absolute;
    left: 1.1rem;
}

.footer .desc .bit-game {
    font-size: 0.2rem;
    line-height: 0.4rem;
    font-weight: 600;
    padding-top: 0.1rem;
}

.footer .desc .subtitle {
    font-size: 0.12rem;
    line-height: 0.1rem;
    word-break: keep-all;
}

.footer .btn_down {
    position: absolute;
    right: 0.1rem;
    top: 0.2rem;
    width: 1.8rem;
    height: 0.6rem;
    background-color: #23a820;
    font-size: 0.3rem;
    color: #fff;
    text-align: center;
    border-radius: 0.1rem;
    line-height: 0.6rem;
}

.show {
    display: block;
}

.hide {
    display: none;
}