:root {
            --brand-red: #ff2849;
            --brand-orange: #ff5e3a;
            --brand-gold: #ffb800;
            --dark-glass: rgba(12, 12, 12, 0.9);
            --text-main: #2c3e50;
            --text-muted: #7f8c8d;
            --bg-light: #fff9f9;
            --transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        
        body { 
            font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; 
            line-height: 1.6; 
            color: var(--text-main); 
            background-color: #fff; 
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        .container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }

        /* --- 1. 导航栏：平直设计 --- */
        .header { 
            background: var(--dark-glass); 
            backdrop-filter: blur(15px); 
            -webkit-backdrop-filter: blur(15px); 
            padding: 12px 0; 
            position: fixed; 
            top: 0; 
            width: 100%; 
            z-index: 1000; 
            border-bottom: 1px solid rgba(255, 255, 255, 0.1); 
        }
        .nav { display: flex; justify-content: space-between; align-items: center; }
        .logo-group { display: flex; align-items: center; gap: 12px; text-decoration: none; }
        .logo-img { 
            width: 38px; height: 38px; 
            background: linear-gradient(135deg, var(--brand-red), var(--brand-orange)); 
            border-radius: 10px; 
            display: flex; align-items: center; justify-content: center; 
            color: white; font-weight: 900; font-size: 20px; 
        }
        .logo-text { font-size: 24px; font-weight: 800; color: #fff; letter-spacing: 1px; }
        .nav-btn { background: var(--brand-red); color: white; padding: 8px 18px; border-radius: 50px; text-decoration: none; font-size: 14px; font-weight: bold; }

        /* --- 2. Hero 区域：恢复红色下载按钮 + 底部波浪 --- */
        .hero { 
            padding: 180px 0 120px; text-align: center; 
            background: linear-gradient(135deg, #2b2b2b 0%, #000000 100%); 
            color: white; position: relative; 
        }
        .hero h1 { font-size: clamp(2.2rem, 6vw, 3.5rem); margin-bottom: 20px; background: linear-gradient(to right, #fff, var(--brand-gold)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; font-weight: 800; }
        .hero p { font-size: 1.2rem; color: rgba(255, 255, 255, 0.7); margin-bottom: 45px; }
        
        /* 恢复红色下载按钮样式 */
        .hero-download-btn { 
            display: inline-block;
            background: var(--brand-red); 
            color: white; 
            padding: 16px 40px; 
            border-radius: 14px; 
            text-decoration: none; 
            font-weight: 800; 
            transition: var(--transition);
            box-shadow: 0 10px 20px rgba(255, 40, 73, 0.3);
        }
        .hero-download-btn:hover { transform: translateY(-3px); box-shadow: 0 15px 30px rgba(255, 40, 73, 0.4); }

        .hero-wave { position: absolute; bottom: -1px; left: 0; width: 100%; line-height: 0; }
        .hero-wave svg { width: 100%; height: 80px; }

        /* --- 公共标题样式 --- */
        .section-header { text-align: center; margin-bottom: 60px; }
        .section-header h2 { font-size: 2.2rem; position: relative; display: inline-block; padding-bottom: 15px; }
        .section-header h2::after { content: ''; position: absolute; bottom: 0; left: 50%; width: 50px; height: 4px; background: var(--brand-red); transform: translateX(-50%); border-radius: 2px; }

        /* --- 3. 为什么选择我们 --- */
        .features { padding: 100px 0; background-color: var(--bg-light); }
        .features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 30px; }
        .feature-card { background: #fff; padding: 40px 30px; border-radius: 24px; text-align: center; transition: var(--transition); border: 1px solid #eee; display: flex; flex-direction: column; align-items: center; }
        .icon-box { width: 70px; height: 70px; background: #fff1f2; border-radius: 18px; display: flex; align-items: center; justify-content: center; font-size: 30px; margin-bottom: 20px; flex-shrink: 0; }
        .feature-card:hover { transform: translateY(-10px); box-shadow: 0 20px 40px rgba(255, 40, 73, 0.1); border-color: var(--brand-red); }

        /* --- 4. 新手教程 --- */
        .tutorial-section { padding: 100px 0; background-color: #fff; }
        .tutorial-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }
        .tutorial-item { text-align: center; padding: 30px; border-radius: 24px; display: flex; flex-direction: column; align-items: center; transition: var(--transition); }
        .step-blob { width: 65px; height: 65px; background: linear-gradient(135deg, var(--brand-red), var(--brand-orange)); color: white; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 26px; font-weight: 800; margin-bottom: 25px; flex-shrink: 0; }

        /* --- 5. 常见问答 --- */
        .faq-section { padding: 100px 0; background-color: var(--bg-light); }
        .faq-container { max-width: 850px; margin: 0 auto; }
        .faq-item { background: #fff; border-radius: 18px; padding: 30px; margin-bottom: 15px; border: 1px solid #f0f0f0; }
        .faq-q { font-weight: 700; color: #333; font-size: 18px; margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
        .faq-q::before { content: 'Q'; color: var(--brand-red); font-size: 22px; font-style: italic; }
        .faq-a { color: var(--text-muted); font-size: 16px; line-height: 1.8; padding-left: 32px; border-left: 3px solid #fef0f0; }

        /* --- 6. 下载区域：容器设计 --- */
        .download-zone { 
            background: linear-gradient(135deg, #e62340 0%, #c21e36 100%); 
            color: white; text-align: center; padding: 100px 0 0 0; overflow: hidden; 
        }
        .download-zone h2 { font-size: 2.6rem; margin-bottom: 15px; }
        .download-zone p { opacity: 0.85; margin-bottom: 45px; font-size: 1.1rem; }
        .btn-group { display: flex; justify-content: center; gap: 20px; margin-bottom: 60px; flex-wrap: wrap; }
        .download-btn-white { background: #fff; color: var(--brand-red); padding: 16px 40px; border-radius: 14px; text-decoration: none; font-weight: 800; transition: var(--transition); }
        
        .app-display { max-width: 800px; margin: 0 auto; padding: 0 20px; }
        .app-display img { width: 100%; height: auto; display: block; border-radius: 20px 20px 0 0; box-shadow: 0 -10px 40px rgba(0,0,0,0.3); }

        .footer { background: #121212; color: #777; padding: 60px 0 40px; text-align: center; }

        /* 移动端适配 */
        @media (max-width: 768px) {
            .features-grid { grid-template-columns: 1fr; gap: 15px; }
            .feature-card { flex-direction: row; text-align: left; padding: 20px; gap: 20px; }
            .icon-box { width: 55px; height: 55px; font-size: 24px; margin-bottom: 0; }
            .tutorial-grid { grid-template-columns: 1fr; gap: 10px; }
            .tutorial-item { flex-direction: row; text-align: left; padding: 20px; gap: 20px; background: #fafafa; }
            .step-blob { width: 45px; height: 45px; font-size: 18px; margin-bottom: 0; }
        }

        .reveal { opacity: 0; transform: translateY(30px); transition: 0.8s ease-out; }
        .reveal.active { opacity: 1; transform: translateY(0); }