/* 全局重置 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            -webkit-tap-highlight-color: transparent;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
            background-color: #f0f2f5; /* 要求的灰色背景 */
            display: flex;
            justify-content: center;
            min-height: 100vh;
        }

        /* 主容器：模拟手机屏幕宽度 */
        .container {
            width: 100%;
            max-width: 750px; /* 限制最大宽度适配PC */
            background:url(../images/bg.jpg);
            background-size:100% 100%;
            position: relative;
            box-shadow: 0 0 20px rgba(0,0,0,0.1);
            overflow-x: hidden;
        }

        /* 顶部导航栏区域 (Logo + 联系我们) */
        .header-nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 20px;
        }

        .img-logo {
            height: 40px;
            width: auto;
        }

        .btn-contact-img {
            height: 36px;
            width: auto;
            cursor: pointer;
        }

        /* 大标题区域 */
        .hero-title-area {
            text-align: center;
            padding: 20px 0;
        }

        .img-main-title {
            width: 90%;
            max-width: 500px;
            height: auto;
            display: block;
            margin: 0 auto;
        }

        /* 下载按钮组 */
        .download-section {
            padding: 20px;
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .btn {
            display: block;
            width: 100%;
            padding: 14px 0;
            border-radius: 8px;
            text-align: center;
            text-decoration: none;
            font-size: 16px;
            font-weight: bold;
            transition: opacity 0.2s;
            border: none;
            cursor: pointer;
        }

        .btn:active {
            opacity: 0.8;
        }

        /* 主下载按钮 (蓝色) */
        .btn-primary {
            background: linear-gradient(90deg, #007aff, #2b95ff);
            color: white;
            box-shadow: 0 4px 10px rgba(0, 122, 255, 0.3);
        }

        /* 系统下载行 (iOS/Android) */
        .system-row {
            display: flex;
            gap: 15px;
        }

        .btn-system {
            flex: 1;
            background: white;
            border: 1px solid #e0e0e0;
            color: #333;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
        }

        /* 已安装打开按钮 */
        .btn-secondary {
            background: white;
            border: 1px solid #e0e0e0;
            color: #007aff;
        }

        /* 中间内容区 (登录框 + 提示) */
        .middle-content {
            padding: 0 20px 20px;
        }

        .img-module-middle {
            width: 100%;
            height: auto;
            border-radius: 12px;
            margin-bottom: 20px;
            display: block;
        }

        /* 底部温馨提示区 */
        .bottom-tip-area {
            padding: 0 20px 10px;
        }

        .img-module-bottom {
            width: 100%;
            height: auto;
            border-radius: 12px;
            display: block;
        }

        /* 版权信息 */
        .footer {
            text-align: center;
            padding: 20px;
            color: #222;
            font-size: 20x;
        }

        /* 简单的图标SVG模拟 (仅用于按钮内部装饰，非图片替代部分) */
        .icon-apple { width: 24px; height: 24px;background:url(../images/apple-logo.png) no-repeat;background-size: 100% 100%;}
        .icon-android{ width: 24px; height: 24px;background:url(../images/android-logo.png) no-repeat;background-size: 100% 100%;}
        .icon-up::before { content: "↑"; margin-right: 5px; }