* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        :root {
            --primary: #00B4D8;
            --primary-dark: #0077B6;
            --accent: #06D6A0;
            --accent-dark: #05A87D;
            --bg-soft: #F0F9FF;
            --bg-card: #FFFFFF;
            --text-main: #1B2A41;
            --text-dim: #6B7A90;
            --border-soft: #E2EEF9;
        }
        body {
            font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
            line-height: 1.7;
            color: var(--text-main);
            background: linear-gradient(160deg, #F0F9FF 0%, #E8F8F5 50%, #F5FBFF 100%);
            background-attachment: fixed;
            overflow-x: hidden;
        }
        a {
            text-decoration: none;
        }

        /* ===== 导航栏：白色简洁 + 柔和阴影 ===== */
        .navbar {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 72px;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border-soft);
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 8%;
            z-index: 9999;
            box-shadow: 0 2px 20px rgba(0, 180, 216, 0.08);
        }
        .nav-left {
            display: flex;
            align-items: center;
        }
        .nav-left img {
            width: 42px;
            height: 42px;
            border-radius: 12px;
            margin-right: 14px;
            box-shadow: 0 4px 12px rgba(0, 180, 216, 0.25);
        }
        .nav-left span {
            font-size: 23px;
            font-weight: 800;
            letter-spacing: 1px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }

        /* ===== Hero 区域：大圆角渐变卡片 ===== */
        .hero {
            padding: 150px 8% 90px;
            display: flex;
            justify-content: center;
            align-items: center;
            text-align: center;
            position: relative;
        }
        .hero-info {
            flex: 1;
            max-width: 820px;
            background: linear-gradient(160deg, #FFFFFF 0%, #F5FCFF 100%);
            border-radius: 40px;
            padding: 70px 60px 65px;
            box-shadow:
                0 20px 60px rgba(0, 180, 216, 0.12),
                0 4px 16px rgba(0, 0, 0, 0.03);
            border: 1px solid rgba(255, 255, 255, 0.8);
            position: relative;
            overflow: hidden;
        }
        .hero-info::before {
            content: "";
            position: absolute;
            top: -120px;
            right: -120px;
            width: 320px;
            height: 320px;
            background: radial-gradient(circle, rgba(6, 214, 160, 0.18) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .hero-info::after {
            content: "";
            position: absolute;
            bottom: -140px;
            left: -100px;
            width: 360px;
            height: 360px;
            background: radial-gradient(circle, rgba(0, 180, 216, 0.15) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .hero-info h1 {
            font-size: 46px;
            font-weight: 900;
            letter-spacing: 1px;
            line-height: 1.3;
            margin-bottom: 26px;
            color: var(--text-main);
            position: relative;
            z-index: 1;
        }
        .hero-info h1 span {
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }
        .hero-info p {
            font-size: 18px;
            color: var(--text-dim);
            margin-bottom: 44px;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
            line-height: 1.9;
            position: relative;
            z-index: 1;
        }

        /* ===== 下载按钮：柔和渐变 + 圆润质感 ===== */
        .dl-group {
            display: flex;
            gap: 20px;
            justify-content: center;
            position: relative;
            z-index: 1;
        }
        .dl-item {
            padding: 17px 44px;
            border-radius: 50px;
            font-size: 17px;
            font-weight: 700;
            letter-spacing: 0.5px;
            color: #fff;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            transition: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
            box-shadow: 0 8px 24px rgba(0, 180, 216, 0.28);
        }
        .android {
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
        }
        .ios {
            background: linear-gradient(135deg, var(--accent), var(--accent-dark));
            box-shadow: 0 8px 24px rgba(6, 214, 160, 0.3);
        }
        .dl-item:hover {
            transform: translateY(-4px) scale(1.03);
            box-shadow: 0 14px 36px rgba(0, 180, 216, 0.4);
        }
        .ios:hover {
            box-shadow: 0 14px 36px rgba(6, 214, 160, 0.42);
        }
        .dl-item:active {
            transform: translateY(-1px) scale(0.99);
        }

        /* ===== 特性卡片：白卡悬浮 + 顶部色条 ===== */
        .features {
            padding: 60px 8%;
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 26px;
            background: transparent;
            position: relative;
            z-index: 1;
        }
        .feat-card {
            background: var(--bg-card);
            border-radius: 24px;
            padding: 40px 24px 34px;
            text-align: center;
            transition: all 0.4s ease;
            box-shadow: 0 6px 24px rgba(0, 180, 216, 0.08);
            border: 1px solid var(--border-soft);
            position: relative;
            overflow: hidden;
        }
        .feat-card::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 4px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
            opacity: 0.8;
            transition: opacity 0.3s;
        }
        .feat-card::after {
            content: "✦";
            display: block;
            font-size: 36px;
            line-height: 1;
            margin-bottom: 18px;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }
        .feat-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 18px 40px rgba(0, 180, 216, 0.18);
            border-color: rgba(0, 180, 216, 0.3);
        }
        .feat-card h3 {
            margin-bottom: 12px;
            font-size: 19px;
            font-weight: 700;
            color: var(--text-main);
            letter-spacing: 0.5px;
        }
        .feat-card p {
            font-size: 14.5px;
            color: var(--text-dim);
            line-height: 1.7;
        }

        /* ===== 详情行：左右交替 + 柔和装饰 ===== */
        .app-detail {
            padding: 70px 8% 30px;
            background: transparent;
            position: relative;
            z-index: 1;
        }
        .row {
            display: flex;
            align-items: center;
            gap: 70px;
            margin-bottom: 100px;
        }
        .row.reverse {
            flex-direction: row-reverse;
        }
        .row-img {
            flex: 0 0 36%;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 240px;
            position: relative;
        }
        .row-img::before {
            content: "";
            position: absolute;
            width: 220px;
            height: 220px;
            border-radius: 40px;
            background: linear-gradient(135deg, rgba(0, 180, 216, 0.12), rgba(6, 214, 160, 0.12));
            transform: rotate(12deg);
            transition: transform 0.5s ease;
        }
        .row-img::after {
            content: "◎";
            font-size: 100px;
            line-height: 1;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            position: relative;
            z-index: 1;
            animation: float-soft 3.5s ease-in-out infinite alternate;
        }
        @keyframes float-soft {
            0% { transform: translateY(0); }
            100% { transform: translateY(-10px); }
        }
        .row:hover .row-img::before {
            transform: rotate(0deg) scale(1.05);
        }
        .row-text {
            flex: 1;
        }
        .row-text h2 {
            font-size: 34px;
            font-weight: 800;
            margin-bottom: 22px;
            color: var(--text-main);
            letter-spacing: 0.5px;
            position: relative;
            line-height: 1.35;
        }
        .row-text h2::after {
            content: "";
            display: block;
            width: 55px;
            height: 4px;
            margin-top: 14px;
            border-radius: 4px;
            background: linear-gradient(90deg, var(--primary), var(--accent));
        }
        .row-text p {
            font-size: 17px;
            color: var(--text-dim);
            line-height: 1.9;
        }

        /* ===== 页脚：柔和浅色 ===== */
        footer {
            background: linear-gradient(180deg, #FFFFFF 0%, #EAF7FF 100%);
            border-top: 1px solid var(--border-soft);
            color: var(--text-dim);
            padding: 70px 8% 40px;
            text-align: center;
            position: relative;
            z-index: 1;
        }
        .footer-nav {
            margin-bottom: 35px;
        }
        .footer-nav a {
            color: var(--text-dim);
            margin: 0 18px;
            font-size: 14.5px;
            letter-spacing: 0.5px;
            transition: all 0.3s;
        }
        .footer-nav a:hover {
            color: var(--primary);
            text-shadow: 0 0 12px rgba(0, 180, 216, 0.3);
        }
        .copy {
            font-size: 13px;
            border-top: 1px solid var(--border-soft);
            padding-top: 30px;
            line-height: 2;
            color: #8A99AE;
        }

        /* ===== 移动端适配 ===== */
        @media (max-width: 992px) {
            .features {
                grid-template-columns: repeat(2, 1fr);
            }
            .hero-info h1 {
                font-size: 38px;
            }
            .hero-info {
                padding: 55px 40px 50px;
            }
        }
        @media (max-width: 768px) {
            .navbar {
                padding: 0 5%;
                height: 65px;
            }
            .nav-left img {
                width: 36px;
                height: 36px;
            }
            .nav-left span {
                font-size: 20px;
            }
            .hero {
                padding: 120px 5% 60px;
            }
            .hero-info {
                padding: 45px 26px 42px;
                border-radius: 30px;
            }
            .hero-info h1 {
                font-size: 28px;
                letter-spacing: 0.5px;
            }
            .hero-info p {
                font-size: 15.5px;
                margin-bottom: 34px;
            }
            .dl-group {
                flex-direction: column;
                gap: 14px;
                width: 100%;
                max-width: 400px;
                margin: 0 auto;
            }
            .dl-item {
                width: 100%;
                padding: 18px 20px;
                font-size: 18px;
            }
            .features {
                grid-template-columns: repeat(2, 1fr);
                gap: 16px;
                padding: 40px 5%;
            }
            .feat-card {
                padding: 28px 16px 24px;
                border-radius: 18px;
            }
            .feat-card::after {
                font-size: 28px;
                margin-bottom: 12px;
            }
            .feat-card h3 {
                font-size: 16px;
            }
            .feat-card p {
                font-size: 13px;
            }
            .app-detail {
                padding: 50px 6% 10px;
            }
            .row,
            .row.reverse {
                flex-direction: column;
                text-align: center;
                gap: 30px;
                margin-bottom: 65px;
            }
            .row-img {
                flex: none;
                width: 100%;
                min-height: 170px;
            }
            .row-img::before {
                width: 160px;
                height: 160px;
                border-radius: 30px;
            }
            .row-img::after {
                font-size: 76px;
            }
            .row-text h2 {
                font-size: 26px;
            }
            .row-text h2::after {
                margin: 12px auto 0;
            }
            .row-text p {
                font-size: 15px;
            }
            footer {
                padding: 50px 6% 30px;
            }
            .footer-nav a {
                margin: 0 10px;
                font-size: 13px;
            }
        }
        @media (max-width: 400px) {
            .features {
                grid-template-columns: 1fr;
            }
            .hero-info h1 {
                font-size: 24px;
            }
        }