* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
        }

        body {
            background: linear-gradient(145deg, #f8faff 0%, #f0f5fe 100%);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 24px 5px;
        }

        .download-card {
            max-width: 560px;
            width: 100%;
            background: rgba(255,255,255,0.85);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid rgba(255,255,255,0.6);
            border-radius: 48px 48px 40px 40px;
            box-shadow: 0 30px 60px rgba(0, 10, 30, 0.15), 0 10px 25px rgba(0, 0, 0, 0.05);
            padding: 40px 32px 48px;
            text-align: center;
            transition: all 0.2s ease;
        }

        /* logo 區域 */
        .logo-wrapper {
            display: flex;
            justify-content: center;
            align-items: center;
            margin-bottom: 20px;
        }
        
        .logo {
            width: 88px;
            height: 88px;
            background: #0b1c3a00;
            border-radius: 28px;
            display: flex;
            align-items: center;
            justify-content: center;
            /*box-shadow: 0 15px 30px -8px rgba(0, 35, 80, 0.3);*/
            
        }

        .logo span {
            font-size: 42px;
            font-weight: 700;
            color: white;
            letter-spacing: 1px;
            filter: drop-shadow(0 2px 3px rgba(0,0,0,0.2));
        }

        h1 {
            font-size: 2.2rem;
            font-weight: 700;
            background: linear-gradient(145deg, #0b1e3a, #203a6b);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin: 8px 0 6px;
            letter-spacing: -0.5px;
        }

        .subhead {
            font-size: 1.15rem;
            color: #4a5a72;
            font-weight: 400;
            margin-bottom: 12px;
            border-bottom: 2px dashed rgba(78, 115, 180, 0.2);
            padding-bottom: 18px;
            display: inline-block;
            width: 100%;
        }

        .description {
            background: rgba(255,255,255,0.5);
            border-radius: 32px;
            padding: 22px 20px;
            margin: 18px 0 28px;
            border: 1px solid rgba(255,255,255,0.9);
            backdrop-filter: blur(4px);
            color: #1e2d49;
            font-size: 1.02rem;
            line-height: 1.6;
            text-align: center;
            box-shadow: inset 0 1px 4px rgba(255,255,255,0.8), 0 8px 12px -8px rgba(0,20,50,0.1);
        }

        .description strong {
            color: #1d3a6d;
            font-weight: 600;
        }

        .device-tag {
            display: inline-block;
            background: #ffffffcc;
            border-radius: 50px;
            padding: 6px 18px;
            margin: 8px 0 18px;
            font-size: 0.9rem;
            font-weight: 500;
            color: #1b3a5e;
            border: 1px solid white;
            box-shadow: 0 4px 10px rgba(0,0,0,0.02);
            backdrop-filter: blur(4px);
        }

        .download-area {
            margin-top: 24px;
            display: flex;
            flex-direction: column;
            gap: 16px;
        }

        .download-btn {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 12px;
            background: #1669efd9;
            border: none;
            border-radius: 100px;
            padding: 18px 28px;
            color: white;
            font-size: 1.4rem;
            font-weight: 600;
            text-decoration: none;
            transition: all 0.2s ease;
            box-shadow: 0 20px 30px -10px rgba(12, 30, 60, 0.4);
            border: 1px solid rgba(255,255,255,0.3);
            backdrop-filter: blur(4px);
            cursor: pointer;
            width: 100%;
            
        }

        .download-btn i {
            font-size: 1.8rem;
            filter: drop-shadow(0 2px 2px rgba(0,0,0,0.2));
        }

        .download-btn:hover {
            background: #163257;
            transform: scale(1.02);
            box-shadow: 0 25px 35px -8px #0a2540;
        }

        .download-btn:active {
            transform: scale(0.98);
        }

        .alt-buttons {
            display: flex;
            gap: 12px;
            justify-content: center;
            margin-top: 8px;
        }

        .alt-btn {
            background: rgba(255,255,255,0.6);
            backdrop-filter: blur(8px);
            border: 1px solid white;
            border-radius: 60px;
            padding: 12px 4px;
            flex: 1;
            color: #1d2f4b;
            font-weight: 500;
            font-size: 1rem;
            text-decoration: none;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            transition: all 0.15s;
            box-shadow: 0 6px 28px #357ae8;
        }

        .alt-btn i {
            font-size: 1.3rem;
            opacity: 0.8;
        }

        .alt-btn:hover {
            background: white;
            border-color: #cddff5;
        }

        .footnote {
            margin-top: 30px;
            color: #536b8a;
            font-size: 0.85rem;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 20px;
            flex-wrap: wrap;
        }

        .footnote a {
            color: #1d3a6d;
            text-decoration: none;
            font-weight: 500;
            border-bottom: 1px dotted #a0b8d0;
        }

        /* 模拟小图标 - 因为不能加载外部字体库, 用 unicode/emoji */
        .icon-apple:after { content: "./apple-logo.png"; }
        .icon-android:after { content: "📱"; }

        .ios-highlight {
            background: linear-gradient(145deg, #1d2e4a, #14233e);
        }

        /* 识别设备相关样式 (js 控制显示隐藏) */
        .detected-badge {
            background: #35a47b;
            color: white;
            border-radius: 60px;
            padding: 6px 18px;
            font-size: 0.85rem;
            font-weight: 500;
            display: inline-block;
            margin-top: 8px;
            box-shadow: 0 4px 10px rgba(52, 168, 83, 0.3);
            letter-spacing: 0.3px;
        }

        /* 简单响应式 */
       @media (max-width: 430px) {
    .download-card { padding: 30px 18px 40px; }
    h1 { font-size: 1.9rem; }

    .download-btn {
        font-size: 1.2rem;
        padding: 5px 20px;

        /* 心跳每3秒触发一次 */
        animation:
            heartbeat-soft 3s infinite,
            pulse-glow 3s infinite;

        transform-origin: center;
    }
}
        /* ===== 自动心跳动画 ===== */
@keyframes heartbeat-soft {
    0%   { transform: scale(1); }
    8%   { transform: scale(1.06); }
    16%  { transform: scale(1); }
    24%  { transform: scale(1.04); }
    32%  { transform: scale(1); }
    100% { transform: scale(1); }
}

/* 呼吸光效 */
@keyframes pulse-glow {
    0% {
        box-shadow: 0 20px 30px -10px rgba(12, 30, 60, 0.4);
    }
    50% {
        box-shadow: 0 25px 40px -6px rgba(60, 140, 255, 0.55);
    }
    100% {
        box-shadow: 0 20px 30px -10px rgba(12, 30, 60, 0.4);
    }
}