/* 响应式字体大小 - 基于375px设计稿, base=50px */
html {
    font-size: 400%; /* 64px for 480px+ */
}
@media screen and (max-width: 383px) {
    html { font-size: 312.5%; } /* 50px */
}
@media screen and (min-width: 384px) and (max-width: 399px) {
    html { font-size: 320%; } /* 51.2px */
}
@media screen and (min-width: 400px) and (max-width: 413px) {
    html { font-size: 333.3%; } /* 53.3px */
}
@media screen and (min-width: 414px) and (max-width: 431px) {
    html { font-size: 345%; } /* 55.2px */
}
@media screen and (min-width: 432px) and (max-width: 479px) {
    html { font-size: 360%; } /* 57.6px */
}

/* 基础样式 */
body {
    font-family: Arial, sans-serif, MicrosoftYaHei;
    font-weight: 400;
    background: url('../img/mbg.jpg') no-repeat center center fixed;
    background-size: cover;
    min-height: 100vh;
    overflow-y: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: 20px;
}
body::-webkit-scrollbar {
    display: none;
}

/* 头部区域 */
.header {
    position: relative;
    width: 100%;
    height: 169px;
    overflow: visible;
}
.header-bg {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
}
.logo-wrap {
    position: absolute;
    bottom: -50px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}
.logo {
    width: 100px;
    height: 103px;
    display: block;
    border-radius: 18px;
}

/* 主标题 */
.main-title {
    text-align: center;
    color: #000000;
    font-size: 0.48rem;
    font-weight: 400;
    margin-top: 60px;
    margin-bottom: 25px;
}

/* 下载按钮区 */
.btn-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 0;
    padding-top: 0;
}
.btn-download {
    display: block;
    width: 63%;
    max-width: 290px;
    margin-bottom: 15px;
    text-align: center;
}
.btn-download img {
    width: 100%;
    height: auto;
    display: block;
}
.btn-download:active {
    opacity: 0.85;
}

/* 提示文字 */
.tip-text {
    text-align: center;
    color: #666666;
    font-size: 16px;
    margin-top: 20px;
    margin-bottom: 20px;
}

/* 苹果推荐区 */
.apple-recommend {
    text-align: center;
    padding: 20px 0;
    background-color: #f5f5f5;
}
.recommend-title {
    color: #00AEEF;
    font-size: 0.32rem;
    font-weight: bold;
    margin-bottom: 0.15rem;
}
.recommend-desc {
    color: #666666;
    font-size: 0.22rem;
    line-height: 1.8;
}
.install-btn {
    display: inline-block;
    width: 125px;
    height: 40px;
    line-height: 40px;
    background-color: #CD3C29;
    color: #FFFFFF;
    font-size: 14px;
    text-align: center;
    border-radius: 5px;
    margin-top: 15px;
    text-decoration: none;
}
.install-btn:active,
.install-btn:hover {
    opacity: 0.85;
}

/* 二维码区 */
.qrcode-section {
    text-align: center;
    padding: 0.3rem 0;
}
.qrcode-title {
    color: #000000;
    font-size: 0.3rem;
    margin-bottom: 0.2rem;
}
.qrcode-img {
    display: inline-block;
}
.qrcode-img img {
    width: 225px;
    height: 225px;
    display: block;
}

/* 浮动按钮 */
.float-btns {
    position: fixed;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.float-btn {
    display: block;
    width: 40px;
    height: 40px;
}
.float-btn img {
    width: 100%;
    height: 100%;
    display: block;
}
.float-btn:active {
    opacity: 0.8;
}

/* 教程弹窗 */
.help_div {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 999;
    width: 100%;
    height: 100%;
    overflow: hidden;
    max-width: 500px;
    margin: 0 auto;
    background-color: #fff;
}

.help-scroll {
    position: relative;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
    overflow-y: auto;
    will-change: transform;
    -webkit-overflow-scrolling: touch;
    height: 100%;
}

.help-close {
    display: flex;
    position: absolute;
    top: 50px;
    left: 10px;
    z-index: 1;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    color: #fff;
    background-color: rgba(0, 0, 0, 0.5);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 2px solid #fff;
    font-size: 12px;
    text-decoration: none;
}

.help-close svg {
    width: 20px;
    height: 20px;
}

/* 微信遮罩提示 */
.wechat-mask {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}
.mask-content {
    background: #fff;
    border-radius: 10px;
    padding: 30px 20px;
    text-align: center;
    width: 80%;
    max-width: 300px;
}
.mask-content p {
    color: #333;
    font-size: 16px;
    line-height: 1.6;
}