* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        /* 熊猫主题：纯黑白配色 */
        :root {
            --panda-black: #000000;
            --panda-white: #ffffff;
            --panda-light: #f1f1f1;
            --panda-gray: #888888;
            --panda-dark: #222222;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background-color: var(--panda-white);
            color: var(--panda-black);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        a {
            text-decoration: none;
        }

        img {
            max-width: 100%;
            display: block;
        }

        /* 统一LOGO图标样式 */
        .logo-icon {
            width: 36px;
            height: 36px;
            object-fit: contain;
            display: inline-block;
        }
        .logo-tag-icon {
            width: 20px;
            height: 20px;
            object-fit: contain;
            display: inline-block;
            vertical-align: middle;
            margin-right: 6px;
        }

        /* 导航栏 */
        .navbar {
            position: fixed;
            top: 0; left: 0;
            width: 100%;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid #eee;
            z-index: 999;
        }

        .nav-inner {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            height: 70px;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .logo-area {
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .logo-text {
            font-size: 22px;
            font-weight: 800;
            color: var(--panda-black);
        }

        .logo-desc {
            font-size: 12px;
            color: #999;
            font-weight: 400;
            margin-left: 4px;
        }

        .nav-menu {
            display: none;
            gap: 30px;
        }

        .nav-menu a {
            font-size: 15px;
            font-weight: 500;
            color: #333;
            transition: 0.2s;
        }

        .nav-menu a:hover {
            color: var(--panda-black);
        }

        .download-btn-small {
            padding: 9px 20px;
            background: var(--panda-black);
            color: var(--panda-white);
            border-radius: 50px;
            font-size: 14px;
            font-weight: 600;
            opacity: 0;
            transform: translateY(-5px);
            transition: 0.3s;
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .download-btn-small img {
            width: 24px;
            height: 24px;
            object-fit: contain;
        }

        .download-btn-small.show {
            opacity: 1;
            transform: translateY(0);
        }

        /* 头部banner */
        .banner {
            padding: 120px 20px 80px;
            background: var(--panda-light);
        }

        .banner-inner {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 50px;
        }

        .banner-left {
            width: 100%;
            text-align: center;
        }

        .banner-tag {
            display: inline-flex;
            align-items: center;
            padding: 8px 18px;
            background: var(--panda-white);
            border: 1px solid #ddd;
            border-radius: 50px;
            font-size: 14px;
            color: var(--panda-black);
            margin-bottom: 25px;
        }

        .banner-title {
            font-size: 38px;
            font-weight: 900;
            line-height: 1.2;
            margin-bottom: 20px;
            color: var(--panda-black);
        }

        .banner-title span {
            color: var(--panda-gray);
        }

        .banner-text {
            font-size: 17px;
            color: #555;
            margin-bottom: 35px;
            line-height: 1.6;
        }

        .banner-text strong {
            color: var(--panda-black);
            text-decoration: underline;
            text-underline-offset: 4px;
        }

        .download-box {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 15px;
            margin-bottom: 40px;
        }

        .download-btn-big {
            padding: 18px 45px;
            background: var(--panda-black);
            color: var(--panda-white);
            border-radius: 20px;
            font-size: 18px;
            font-weight: 700;
            box-shadow: 0 10px 30px rgba(0,0,0,0.15);
            display: inline-flex;
            align-items: center;
            gap: 10px;
            width: 100%;
            max-width: 300px;
            justify-content: center;
            animation: pulse 2s infinite;
        }

        .download-btn-big img {
            width: 28px;
            height: 28px;
            object-fit: contain;
        }

        .safe-info {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 13px;
            color: #777;
        }

        .qrcode-area {
            display: none;
            align-items: center;
            gap: 15px;
        }

        .qrcode {
            padding: 10px;
            background: #fff;
            border: 1px solid #eee;
            border-radius: 10px;
        }

        .qrcode img {
            width: 85px;
            height: 85px;
        }

        .qrcode-text {
            font-size: 12px;
            color: #888;
            line-height: 1.4;
        }

        .banner-right {
            width: 100%;
            display: flex;
            justify-content: center;
        }

        .phone-box {
            width: 260px;
            position: relative;
            filter: drop-shadow(0 20px 40px rgba(0,0,0,0.1));
        }

        .phone-box img {
            border-radius: 35px;
        }

        /* 优势板块 */
        .advantages {
            padding: 80px 20px;
            background: var(--panda-white);
        }

        .adv-inner {
            max-width: 1100px;
            margin: 0 auto;
        }

        .adv-title {
            text-align: center;
            margin-bottom: 60px;
        }

        .adv-title h2 {
            font-size: 32px;
            font-weight: 800;
            color: var(--panda-black);
            margin-bottom: 15px;
        }

        .adv-line {
            width: 60px;
            height: 4px;
            background: var(--panda-black);
            margin: 0 auto;
            border-radius: 5px;
        }

        .adv-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 30px;
        }

        .adv-item {
            background: var(--panda-light);
            border: 2px solid var(--panda-black);
            border-radius: 24px;
            padding: 40px 30px;
            text-align: center;
            transition: 0.3s;
        }

        .adv-item:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        }

        .adv-icon {
            width: 70px;
            height: 70px;
            background: var(--panda-black);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 25px;
        }

        .adv-icon img {
            width: 40px;
            height: 40px;
            object-fit: contain;
        }

        .adv-item h3 {
            font-size: 22px;
            font-weight: 700;
            color: var(--panda-black);
            margin-bottom: 15px;
        }

        .adv-item p {
            font-size: 15px;
            color: #555;
            line-height: 1.6;
        }

        /* 步骤流程 */
        .steps {
            padding: 80px 20px;
            background: var(--panda-light);
        }

        .steps-inner {
            max-width: 1000px;
            margin: 0 auto;
        }

        .steps-title {
            text-align: center;
            font-size: 30px;
            font-weight: 800;
            margin-bottom: 50px;
            color: var(--panda-black);
        }

        .steps-box {
            display: grid;
            grid-template-columns: 1fr;
            gap: 25px;
        }

        .step {
            background: var(--panda-white);
            border-radius: 20px;
            padding: 35px 25px;
            text-align: center;
            border: 1px solid #eee;
            position: relative;
        }

        .step-number {
            width: 40px;
            height: 40px;
            background: var(--panda-black);
            color: var(--panda-white);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            position: absolute;
            top: -20px;
            left: 50%;
            transform: translateX(-50%);
        }

        .step h3 {
            font-size: 20px;
            font-weight: 700;
            margin-top: 10px;
            margin-bottom: 10px;
        }

        .step p {
            font-size: 14px;
            color: #666;
        }

        /* 页脚 */
        .footer {
            padding: 50px 20px;
            border-top: 1px solid #eee;
            text-align: center;
            font-size: 13px;
            color: #999;
        }

        .footer-link {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 20px;
        }

        .footer-link a {
            color: #888;
        }

        /* 动画 */
        @keyframes pulse {
            0%,100% { transform: scale(1); }
            50% { transform: scale(1.03); }
        }

        /* 响应式 */
        @media (min-width: 768px) {
            .nav-menu {
                display: flex;
            }
            .banner {
                padding: 150px 20px 100px;
            }
            .banner-inner {
                flex-direction: row;
                align-items: center;
            }
            .banner-left {
                width: 55%;
                text-align: left;
            }
            .banner-right {
                width: 45%;
            }
            .banner-title {
                font-size: 50px;
            }
            .download-box {
                flex-direction: row;
                justify-content: flex-start;
            }
            .download-btn-big {
                width: auto;
            }
            .qrcode-area {
                display: flex;
            }
            .phone-box {
                width: 320px;
            }
            .adv-grid {
                grid-template-columns: repeat(2, 1fr);
            }
            .steps-box {
                grid-template-columns: repeat(3, 1fr);
            }
        }