:root {
            --primary: #ff0055;    /* 品牌玫红 */
            --secondary: #40c4ff;  /* 灵动天蓝 */
            --text-dark: #1a1a1a;
            --text-gray: #666;
            --step-bg: #fdf2f5;
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: "PingFang SC", "Microsoft YaHei", sans-serif; background: #fff; color: var(--text-dark); line-height: 1.6; }
        a { text-decoration: none; }

        /* 导航栏 */
        nav {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 10%;
            height: 70px;
            background: #fff;
            box-shadow: 0 2px 10px rgba(0,0,0,0.02);
            position: sticky;
            top: 0; z-index: 1000;
        }
        .logo { display: flex; align-items: center; gap: 12px; font-size: 22px; font-weight: bold; color: var(--primary); }
        .logo img { height: 42px; border-radius: 10px; }

        /* 主下载展示区 */
        .hero {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 80px 10%;
            background: radial-gradient(circle at top right, var(--step-bg), #fff);
        }
        .hero-text { flex: 1.2; }
        .hero-text h1 { font-size: 46px; margin-bottom: 20px; line-height: 1.2; }
        .hero-text h1 span { color: var(--secondary); }
        .hero-text p { font-size: 18px; color: var(--text-gray); margin-bottom: 45px; }

        .download-group { display: flex; gap: 15px; }
        .btn {
            display: flex; align-items: center; justify-content: center;
            width: 210px; height: 58px; border-radius: 15px;
            font-weight: bold; font-size: 16px; transition: 0.3s; color: #fff;
        }
        .btn-android { background: var(--primary); box-shadow: 0 8px 20px rgba(255,0,85,0.15); }
        .btn-ios { background: #000; }
        .btn:hover { transform: translateY(-3px); filter: brightness(1.1); }

        /* 下载图片 - PC端 */
        .hero-visual { flex: 0.8; display: flex; justify-content: flex-end; }
        .hero-visual img { width: 300px; border-radius: 40px; box-shadow: 0 20px 50px rgba(0,0,0,0.08); }

        /* 安装步骤区块 */
        .setup-section { padding: 90px 10%; text-align: center; }
        .section-title { font-size: 32px; margin-bottom: 50px; position: relative; }
        .section-title::after { content: ""; display: block; width: 40px; height: 4px; background: var(--primary); margin: 15px auto; border-radius: 2px; }
        
        .steps-container { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
        .step-card { padding: 40px 25px; background: var(--step-bg); border-radius: 24px; position: relative; }
        .step-num { 
            position: absolute; top: -20px; left: 50%; transform: translateX(-50%);
            width: 45px; height: 45px; background: var(--primary); color: #fff;
            border-radius: 50%; display: flex; align-items: center; justify-content: center;
            font-weight: bold; font-size: 20px; border: 4px solid #fff;
        }
        .step-card h3 { margin: 15px 0 12px; font-size: 20px; }
        .step-card p { font-size: 14px; color: var(--text-gray); }

        /* 底部信息 */
        .info-footer { padding: 60px 10%; background: #fafafa; display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
        .info-box h2 { font-size: 24px; margin-bottom: 25px; color: var(--primary); }
        .qa-item { background: #fff; padding: 20px; border-radius: 12px; margin-bottom: 15px; border: 1px solid #eee; }

        footer { padding: 40px; text-align: center; color: #bbb; border-top: 1px solid #f0f0f0; font-size: 13px; }

        /* ================= 移动端极致居中适配 ================= */
        @media (max-width: 768px) {
            nav { padding: 0 5%; justify-content: center; }
            .hero {
                flex-direction: column;
                padding: 40px 20px;
                text-align: center;
            }
            .hero-text { width: 100%; margin-bottom: 40px; }
            .hero-text h1 { font-size: 32px; }
            .download-group { flex-direction: column; align-items: center; }
            .btn { width: 85%; max-width: 280px; }

            /* 核心：彻底消除偏移 */
            .hero-visual {
                order: 3;            /* 排在按钮下方 */
                width: 100%;         /* 容器全宽 */
                display: flex;       /* 开启Flex布局 */
                justify-content: center; /* 水平绝对居中 */
                align-items: center; /* 垂直对齐 */
                margin: 30px auto 0; /* 外部间距自动居中 */
                padding: 0;          /* 清除所有可能的内边距 */
            }
            .hero-visual img {
                width: 75%;          /* 手机端图片比例 */
                max-width: 260px;
                margin: 0;           /* 清除边距干扰 */
                border-radius: 30px;
            }

            .steps-container { grid-template-columns: 1fr; gap: 40px; margin-top: 20px; }
            .info-footer { grid-template-columns: 1fr; padding: 40px 20px; }
        }