/* ===== RESET & BASE ===== */
        *,
        *::before,
        *::after {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        :root {
            --primary: #2a6df4;
            --primary-dark: #1a4fb3;
            --primary-light: #e8f0fe;
            --accent: #f5a623;
            --gray-50: #f9fafb;
            --gray-100: #f3f4f6;
            --gray-200: #e5e7eb;
            --gray-300: #d1d5db;
            --gray-600: #6b7280;
            --gray-700: #374151;
            --gray-800: #1f2937;
            --gray-900: #111827;
            --white: #ffffff;
            --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
            --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
            --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
            --radius: 16px;
            --radius-sm: 8px;
            --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        html {
            scroll-behavior: smooth;
            font-size: 16px;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
            background: var(--gray-50);
            color: var(--gray-800);
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        a {
            color: var(--primary);
            text-decoration: none;
            transition: color var(--transition);
        }
        a:hover {
            color: var(--primary-dark);
        }

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

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* ===== SKIP LINK ===== */
        .skip-link {
            position: absolute;
            top: -100%;
            left: 50%;
            transform: translateX(-50%);
            background: var(--primary);
            color: var(--white) !important;
            padding: 12px 24px;
            border-radius: 0 0 var(--radius-sm) var(--radius-sm);
            z-index: 10000;
            font-weight: 600;
        }
        .skip-link:focus {
            top: 0;
        }

        /* ===== HEADER / NAV ===== */
        .site-header {
            background: rgba(255, 255, 255, 0.85);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--gray-200);
            position: sticky;
            top: 0;
            z-index: 1000;
            transition: box-shadow var(--transition);
        }
        .site-header.scrolled {
            box-shadow: var(--shadow-sm);
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 64px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 8px;
            font-size: 1.25rem;
            font-weight: 700;
            color: var(--gray-900);
        }
        .logo-icon {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 36px;
            height: 36px;
            background: var(--primary);
            color: white;
            border-radius: var(--radius-sm);
            font-size: 1.1rem;
            font-weight: 700;
            flex-shrink: 0;
        }
        .logo span {
            color: var(--primary);
        }

        .nav-desktop {
            display: flex;
            align-items: center;
            gap: 28px;
        }
        .nav-desktop a {
            font-size: 0.95rem;
            font-weight: 500;
            color: var(--gray-700);
            position: relative;
        }
        .nav-desktop a::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary);
            transition: width var(--transition);
        }
        .nav-desktop a:hover::after,
        .nav-desktop a:focus::after {
            width: 100%;
        }
        .nav-desktop a:hover {
            color: var(--gray-900);
        }

        .nav-cta {
            background: var(--primary);
            color: var(--white) !important;
            padding: 8px 20px;
            border-radius: 50px;
            font-weight: 600;
            transition: background var(--transition), transform var(--transition);
        }
        .nav-cta::after {
            display: none !important;
        }
        .nav-cta:hover {
            background: var(--primary-dark);
            transform: translateY(-1px);
            color: var(--white) !important;
        }

        /* Mobile Toggle */
        .nav-toggle {
            display: none;
            flex-direction: column;
            gap: 5px;
            background: transparent;
            border: none;
            cursor: pointer;
            padding: 4px;
            border-radius: var(--radius-sm);
        }
        .nav-toggle span {
            display: block;
            width: 26px;
            height: 2.5px;
            background: var(--gray-800);
            border-radius: 2px;
            transition: var(--transition);
            transform-origin: center;
        }
        .nav-toggle.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }
        .nav-toggle.active span:nth-child(2) {
            opacity: 0;
        }
        .nav-toggle.active span:nth-child(3) {
            transform: rotate(-45deg) translate(5px, -5px);
        }

        /* Mobile Nav */
        .nav-mobile {
            display: none;
            flex-direction: column;
            background: var(--white);
            border-top: 1px solid var(--gray-200);
            padding: 20px 0;
            gap: 12px;
            position: absolute;
            top: 64px;
            left: 0;
            right: 0;
            box-shadow: var(--shadow-md);
        }
        .nav-mobile.open {
            display: flex;
        }
        .nav-mobile a {
            padding: 10px 20px;
            font-size: 1rem;
            font-weight: 500;
            color: var(--gray-700);
            border-radius: var(--radius-sm);
            transition: background var(--transition);
        }
        .nav-mobile a:hover {
            background: var(--gray-100);
            color: var(--gray-900);
        }
        .nav-mobile .nav-cta-mobile {
            background: var(--primary);
            color: var(--white) !important;
            text-align: center;
            margin: 4px 20px 0;
            border-radius: 50px;
            padding: 12px;
        }
        .nav-mobile .nav-cta-mobile:hover {
            background: var(--primary-dark);
        }

        /* ===== HERO ===== */
        .hero {
            padding: 60px 0 80px;
            background: linear-gradient(135deg, #f0f7ff 0%, #e8f0fe 100%);
            position: relative;
            overflow: hidden;
        }
        .hero::after {
            content: '';
            position: absolute;
            right: -20%;
            top: -30%;
            width: 600px;
            height: 600px;
            background: radial-gradient(circle, rgba(42, 109, 244, 0.06) 0%, transparent 70%);
            border-radius: 50%;
            pointer-events: none;
        }
        .hero .container {
            position: relative;
            z-index: 1;
        }

        .hero-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 60px;
            align-items: center;
        }

        .hero-content h1 {
            font-size: clamp(2rem, 4.5vw, 3.2rem);
            font-weight: 800;
            line-height: 1.15;
            color: var(--gray-900);
            letter-spacing: -0.02em;
        }
        .hero-content h1 .highlight {
            color: var(--primary);
            position: relative;
        }
        .hero-content h1 .highlight::after {
            content: '';
            position: absolute;
            bottom: 2px;
            left: 0;
            right: 0;
            height: 8px;
            background: rgba(42, 109, 244, 0.15);
            border-radius: 4px;
            z-index: -1;
        }

        .hero-sub {
            font-size: 1.15rem;
            color: var(--gray-600);
            margin-top: 16px;
            max-width: 480px;
            line-height: 1.7;
        }

        .hero-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 14px;
            margin-top: 28px;
        }
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 14px 32px;
            border-radius: 50px;
            font-weight: 600;
            font-size: 1rem;
            border: none;
            cursor: pointer;
            transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
            text-align: center;
        }
        .btn-primary {
            background: var(--primary);
            color: var(--white);
            box-shadow: 0 4px 14px rgba(42, 109, 244, 0.35);
        }
        .btn-primary:hover {
            background: var(--primary-dark);
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(42, 109, 244, 0.4);
        }
        .btn-secondary {
            background: var(--white);
            color: var(--gray-800);
            border: 1.5px solid var(--gray-300);
        }
        .btn-secondary:hover {
            background: var(--gray-100);
            border-color: var(--gray-600);
            transform: translateY(-2px);
        }

        .hero-stats {
            display: flex;
            gap: 40px;
            margin-top: 36px;
        }
        .hero-stats .stat {
            display: flex;
            flex-direction: column;
        }
        .hero-stats .stat-number {
            font-size: 1.6rem;
            font-weight: 700;
            color: var(--gray-900);
        }
        .hero-stats .stat-label {
            font-size: 0.9rem;
            color: var(--gray-600);
        }

        .hero-visual {
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .hero-card {
            background: var(--white);
            padding: 32px 28px;
            border-radius: var(--radius);
            box-shadow: var(--shadow-lg);
            width: 100%;
            max-width: 400px;
            border: 1px solid rgba(255, 255, 255, 0.6);
            backdrop-filter: blur(4px);
        }
        .hero-card .feature-row {
            display: flex;
            align-items: center;
            gap: 14px;
            padding: 14px 0;
            border-bottom: 1px solid var(--gray-100);
        }
        .hero-card .feature-row:last-child {
            border-bottom: none;
        }
        .hero-card .feature-icon {
            width: 40px;
            height: 40px;
            border-radius: var(--radius-sm);
            background: var(--primary-light);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            flex-shrink: 0;
        }
        .hero-card .feature-text {
            font-weight: 500;
            font-size: 0.95rem;
        }
        .hero-card .feature-desc {
            font-size: 0.85rem;
            color: var(--gray-600);
        }

        /* ===== SECTION COMMON ===== */
        .section {
            padding: 70px 0;
        }
        .section-title {
            font-size: clamp(1.6rem, 3vw, 2.4rem);
            font-weight: 700;
            color: var(--gray-900);
            letter-spacing: -0.01em;
            margin-bottom: 12px;
        }
        .section-sub {
            font-size: 1.05rem;
            color: var(--gray-600);
            max-width: 600px;
            line-height: 1.7;
        }
        .section-header {
            text-align: center;
            margin-bottom: 48px;
        }
        .section-header .section-sub {
            margin: 0 auto;
        }

        /* ===== PRODUCT FEATURES ===== */
        #product {
            background: var(--white);
        }
        .features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: 28px;
        }
        .feature-card {
            background: var(--gray-50);
            padding: 28px 22px 30px;
            border-radius: var(--radius);
            transition: transform var(--transition), box-shadow var(--transition);
            border: 1px solid transparent;
        }
        .feature-card:hover {
            transform: translateY(-6px);
            box-shadow: var(--shadow-md);
            border-color: var(--gray-200);
            background: var(--white);
        }
        .feature-card .icon {
            font-size: 2rem;
            margin-bottom: 12px;
            display: block;
        }
        .feature-card h3 {
            font-size: 1.1rem;
            font-weight: 600;
            margin-bottom: 6px;
        }
        .feature-card p {
            font-size: 0.95rem;
            color: var(--gray-600);
            line-height: 1.6;
        }

        /* ===== ABOUT ===== */
        #about {
            background: var(--gray-50);
        }
        .about-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 50px;
            align-items: center;
        }
        .about-content p {
            color: var(--gray-600);
            line-height: 1.8;
            margin-bottom: 16px;
        }
        .about-content p:last-child {
            margin-bottom: 0;
        }
        .about-values {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
            margin-top: 20px;
        }
        .about-values .value-item {
            background: var(--white);
            padding: 16px 18px;
            border-radius: var(--radius-sm);
            border-left: 4px solid var(--primary);
            box-shadow: var(--shadow-sm);
        }
        .about-values .value-item strong {
            display: block;
            font-size: 0.95rem;
        }
        .about-values .value-item span {
            font-size: 0.85rem;
            color: var(--gray-600);
        }

        .about-image {
            background: var(--primary-light);
            border-radius: var(--radius);
            padding: 40px 30px;
            text-align: center;
            min-height: 240px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            border: 2px dashed rgba(42, 109, 244, 0.2);
        }
        .about-image .big-icon {
            font-size: 4rem;
            margin-bottom: 12px;
        }
        .about-image p {
            color: var(--gray-600);
            font-size: 0.95rem;
        }

        /* ===== PRIVACY ===== */
        #privacy {
            background: var(--white);
        }
        .privacy-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 28px;
        }
        .privacy-card {
            background: var(--gray-50);
            padding: 24px 22px;
            border-radius: var(--radius);
            border: 1px solid var(--gray-200);
            transition: border-color var(--transition);
        }
        .privacy-card:hover {
            border-color: var(--primary);
        }
        .privacy-card .icon {
            font-size: 1.6rem;
            margin-bottom: 8px;
            display: block;
        }
        .privacy-card h4 {
            font-size: 1rem;
            font-weight: 600;
            margin-bottom: 4px;
        }
        .privacy-card p {
            font-size: 0.9rem;
            color: var(--gray-600);
            line-height: 1.6;
        }

        /* ===== CONTACT ===== */
        #contact {
            background: var(--gray-50);
        }
        .contact-wrap {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 50px;
            align-items: start;
        }
        .contact-info h3 {
            font-size: 1.3rem;
            font-weight: 600;
            margin-bottom: 12px;
        }
        .contact-info p {
            color: var(--gray-600);
            margin-bottom: 20px;
            line-height: 1.7;
        }
        .contact-detail {
            display: flex;
            align-items: center;
            gap: 14px;
            padding: 12px 0;
            border-bottom: 1px solid var(--gray-200);
        }
        .contact-detail:last-child {
            border-bottom: none;
        }
        .contact-detail .cd-icon {
            width: 36px;
            height: 36px;
            background: var(--primary-light);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.1rem;
            flex-shrink: 0;
        }
        .contact-detail .cd-text {
            font-size: 0.95rem;
        }
        .contact-detail .cd-text strong {
            display: block;
            font-weight: 600;
            color: var(--gray-800);
        }

        .contact-form {
            background: var(--white);
            padding: 32px 30px;
            border-radius: var(--radius);
            box-shadow: var(--shadow-md);
            border: 1px solid var(--gray-200);
        }
        .contact-form label {
            display: block;
            font-weight: 500;
            font-size: 0.9rem;
            margin-bottom: 4px;
            color: var(--gray-700);
        }
        .contact-form input,
        .contact-form textarea {
            width: 100%;
            padding: 12px 16px;
            border: 1.5px solid var(--gray-200);
            border-radius: var(--radius-sm);
            font-size: 1rem;
            font-family: inherit;
            transition: border-color var(--transition), box-shadow var(--transition);
            background: var(--gray-50);
        }
        .contact-form input:focus,
        .contact-form textarea:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 4px rgba(42, 109, 244, 0.1);
            background: var(--white);
        }
        .contact-form .form-group {
            margin-bottom: 18px;
        }
        .contact-form .btn {
            width: 100%;
            justify-content: center;
            padding: 16px;
            font-size: 1.05rem;
        }

        /* ===== FOOTER ===== */
        .site-footer {
            background: var(--gray-900);
            color: var(--gray-300);
            padding: 40px 0 28px;
        }
        .footer-inner {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            gap: 20px;
        }
        .footer-copy {
            font-size: 0.9rem;
        }
        .footer-links {
            display: flex;
            gap: 24px;
            flex-wrap: wrap;
        }
        .footer-links a {
            color: var(--gray-300);
            font-size: 0.9rem;
            transition: color var(--transition);
        }
        .footer-links a:hover {
            color: var(--white);
        }
        .footer-social {
            display: flex;
            gap: 16px;
        }
        .footer-social a {
            color: var(--gray-300);
            font-size: 1.1rem;
            transition: color var(--transition);
        }
        .footer-social a:hover {
            color: var(--white);
        }
        .footer-divider {
            width: 100%;
            border: none;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            margin: 20px 0 16px;
        }
        .footer-bottom {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 12px;
            font-size: 0.8rem;
            color: var(--gray-500);
        }
        .footer-bottom a {
            color: var(--gray-500);
        }
        .footer-bottom a:hover {
            color: var(--gray-300);
        }

        /* ===== RESPONSIVE ===== */
        @media (max-width: 1024px) {
            .hero-grid {
                gap: 40px;
            }
            .about-grid {
                gap: 30px;
            }
            .contact-wrap {
                gap: 30px;
            }
        }

        @media (max-width: 820px) {
            .hero-grid {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .hero-sub {
                margin-left: auto;
                margin-right: auto;
            }
            .hero-actions {
                justify-content: center;
            }
            .hero-stats {
                justify-content: center;
            }
            .hero-visual {
                order: -1;
            }
            .hero-card {
                max-width: 100%;
            }

            .about-grid {
                grid-template-columns: 1fr;
                text-align: center;
            }
            .about-values {
                grid-template-columns: 1fr 1fr;
            }
            .about-image {
                order: -1;
            }

            .contact-wrap {
                grid-template-columns: 1fr;
            }
            .contact-info {
                text-align: center;
            }
            .contact-detail {
                justify-content: center;
            }

            .footer-inner {
                flex-direction: column;
                text-align: center;
            }
            .footer-links {
                justify-content: center;
            }
            .footer-bottom {
                justify-content: center;
                text-align: center;
            }
        }

        @media (max-width: 600px) {
            .nav-desktop {
                display: none;
            }
            .nav-toggle {
                display: flex;
            }

            .hero {
                padding: 40px 0 60px;
            }
            .hero-stats {
                gap: 24px;
                flex-wrap: wrap;
            }
            .hero-stats .stat-number {
                font-size: 1.3rem;
            }

            .section {
                padding: 50px 0;
            }
            .section-header {
                margin-bottom: 32px;
            }

            .features-grid {
                grid-template-columns: 1fr 1fr;
            }
            .about-values {
                grid-template-columns: 1fr;
            }
            .privacy-grid {
                grid-template-columns: 1fr;
            }

            .contact-form {
                padding: 24px 18px;
            }

            .footer-links {
                gap: 16px;
                flex-wrap: wrap;
                justify-content: center;
            }
        }

        @media (max-width: 400px) {
            .features-grid {
                grid-template-columns: 1fr;
            }
            .hero-actions {
                flex-direction: column;
                align-items: center;
            }
            .hero-actions .btn {
                width: 100%;
                max-width: 280px;
            }
            .hero-card {
                padding: 20px 16px;
            }
        }