:root {
            --gtmamk-primary: #FF6600;
            --gtmamk-primary-hover: #e55c00;
            --gtmamk-secondary: #2C3E50;
            --gtmamk-bg-light: #F8FAFC;
            --gtmamk-text-main: #1D1D1F;
            --gtmamk-text-muted: #6E6E73;
            --gtmamk-white: #FFFFFF;
            --gtmamk-shadow: 0 10px 30px rgba(0,0,0,0.08);
            --gtmamk-radius: 20px;
            --gtmamk-container-width: 92vw;
            --gtmamk-max-width: 1360px;
        }

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

        body {
            font-family: "SF Pro SC", "HanHei SC", "PingFang SC", "Microsoft YaHei", sans-serif;
            background-color: var(--gtmamk-bg-light);
            color: var(--gtmamk-text-main);
            line-height: 1.6;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        /* Layout Helpers */
        .gtmamk-container {
            max-width: var(--gtmamk-max-width);
            width: var(--gtmamk-container-width);
            margin: 0 auto;
            position: relative;
        }

        .gtmamk-flex {
            display: flex;
            flex-wrap: wrap;
        }

        .gtmamk-grid {
            display: grid;
            gap: 24px;
        }

        /* Navigation */
        .gtmamk-nav-wrapper {
            position: fixed;
            top: 0;
            width: 100%;
            z-index: 1000;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border-bottom: 1px solid rgba(0,0,0,0.05);
            transition: all 0.3s ease;
        }

        .gtmamk-nav-container {
            height: 72px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 24px;
            flex-wrap: wrap;
        }

        .gtmamk-logo {
            flex-shrink: 0;
            min-width: 0;
        }

        .gtmamk-logo img {
            height: 36px;
            display: block;
        }

        .gtmamk-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 24px;
            min-width: 0;
        }

        .gtmamk-menu a {
            text-decoration: none;
            color: var(--gtmamk-text-main);
            font-size: 15px;
            font-weight: 500;
            transition: color 0.3s;
            word-break: keep-all;
        }

        .gtmamk-menu a:hover {
            color: var(--gtmamk-primary);
        }

        /* Hero Section */
        .gtmamk-hero {
            padding-top: 140px;
            padding-bottom: 80px;
            overflow: hidden;
            background: radial-gradient(circle at 80% 20%, rgba(255, 102, 0, 0.05) 0%, transparent 50%);
        }

        .gtmamk-hero-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
            gap: 48px;
            align-items: center;
        }

        .gtmamk-hero-content {
            min-width: 0;
            word-break: break-word;
        }

        .gtmamk-hero-title {
            font-size: clamp(2.5rem, 5vw + 1rem, 4rem);
            line-height: 1.1;
            font-weight: 800;
            margin-bottom: 24px;
            background: linear-gradient(135deg, #1D1D1F 0%, #434343 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            white-space: normal;
        }

        .gtmamk-hero-subtitle {
            font-size: clamp(1.1rem, 1.5vw + 0.5rem, 1.4rem);
            color: var(--gtmamk-text-muted);
            margin-bottom: 40px;
            max-width: 600px;
        }

        .gtmamk-download-card {
            background: var(--gtmamk-white);
            padding: 40px;
            border-radius: var(--gtmamk-radius);
            box-shadow: var(--gtmamk-shadow);
            border: 1px solid rgba(255, 102, 0, 0.1);
            position: relative;
        }

        .gtmamk-btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--gtmamk-primary);
            color: var(--gtmamk-white);
            padding: 18px 48px;
            border-radius: 50px;
            text-decoration: none;
            font-size: 18px;
            font-weight: 600;
            transition: transform 0.3s, background 0.3s, box-shadow 0.3s;
            margin-bottom: 16px;
            box-shadow: 0 10px 20px rgba(255, 102, 0, 0.2);
            word-break: keep-all;
        }

        .gtmamk-btn-primary:hover {
            background: var(--gtmamk-primary-hover);
            transform: translateY(-2px);
            box-shadow: 0 15px 30px rgba(255, 102, 0, 0.3);
        }

        .gtmamk-hero-image {
            position: relative;
            min-width: 0;
        }

        .gtmamk-hero-image img {
            width: 100%;
            height: auto;
            border-radius: var(--gtmamk-radius);
            box-shadow: 0 20px 40px rgba(0,0,0,0.1);
        }

        /* Lexicon Bento Grid */
        .gtmamk-lexicon-section {
            padding: 96px 0;
            background: var(--gtmamk-white);
        }

        .gtmamk-section-header {
            text-align: center;
            margin-bottom: 64px;
        }

        .gtmamk-section-title {
            font-size: clamp(2rem, 3vw, 2.5rem);
            margin-bottom: 16px;
        }

        .gtmamk-lexicon-grid {
            grid-template-columns: repeat(3, 1fr);
        }

        .gtmamk-lexicon-card {
            background: var(--gtmamk-bg-light);
            padding: 40px;
            border-radius: var(--gtmamk-radius);
            transition: transform 0.3s ease;
            min-width: 0;
            border: 1px solid transparent;
        }

        .gtmamk-lexicon-card:hover {
            transform: translateY(-8px);
            border-color: var(--gtmamk-primary);
        }

        .gtmamk-industry-tag {
            display: inline-block;
            padding: 6px 16px;
            background: rgba(255, 102, 0, 0.1);
            color: var(--gtmamk-primary);
            border-radius: 30px;
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 20px;
        }

        .gtmamk-lexicon-depth {
            font-weight: 700;
            font-size: 20px;
            margin-bottom: 16px;
        }

        .gtmamk-sample-terms {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            margin-top: 16px;
        }

        .gtmamk-term-chip {
            background: var(--gtmamk-white);
            padding: 4px 12px;
            border-radius: 6px;
            font-size: 13px;
            color: var(--gtmamk-text-muted);
            border: 1px solid rgba(0,0,0,0.05);
        }

        /* Safety Section */
        .gtmamk-safety-section {
            padding: 96px 0;
        }

        .gtmamk-safety-box {
            background: var(--gtmamk-secondary);
            color: var(--gtmamk-white);
            border-radius: 32px;
            overflow: hidden;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
        }

        .gtmamk-safety-text {
            flex: 1;
            padding: 64px;
            min-width: 300px;
            word-break: break-word;
        }

        .gtmamk-safety-image {
            flex: 1;
            min-width: 300px;
            line-height: 0;
        }

        .gtmamk-safety-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            min-height: 400px;
        }

        /* Guide Section */
        .gtmamk-guide-section {
            padding: 96px 0;
            background: #fff;
        }

        .gtmamk-guide-container {
            display: flex;
            flex-wrap: wrap;
            gap: 64px;
            align-items: center;
        }

        .gtmamk-guide-visual {
            flex: 1.2;
            min-width: 320px;
        }

        .gtmamk-guide-visual img {
            width: 100%;
            border-radius: var(--gtmamk-radius);
            box-shadow: var(--gtmamk-shadow);
        }

        .gtmamk-guide-steps {
            flex: 0.8;
            min-width: 300px;
        }

        .gtmamk-step-item {
            display: flex;
            gap: 24px;
            margin-bottom: 32px;
            padding-bottom: 32px;
            border-bottom: 1px solid rgba(0,0,0,0.05);
        }

        .gtmamk-step-num {
            width: 40px;
            height: 40px;
            background: var(--gtmamk-primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 700;
            flex-shrink: 0;
        }

        /* Footer */
        .gtmamk-footer {
            background: #1D1D1F;
            color: #A1A1A6;
            padding: 80px 0 40px;
        }

        .gtmamk-footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 48px;
            margin-bottom: 64px;
        }

        .gtmamk-footer-brand h2 {
            color: var(--gtmamk-white);
            margin-bottom: 16px;
            font-size: 24px;
        }

        .gtmamk-footer-links h4 {
            color: var(--gtmamk-white);
            margin-bottom: 24px;
            font-size: 16px;
        }

        .gtmamk-footer-links ul {
            list-style: none;
        }

        .gtmamk-footer-links li {
            margin-bottom: 12px;
        }

        .gtmamk-footer-links a {
            color: #A1A1A6;
            text-decoration: none;
            font-size: 14px;
            transition: color 0.3s;
        }

        .gtmamk-footer-links a:hover {
            color: var(--gtmamk-primary);
        }

        .gtmamk-copyright {
            padding-top: 40px;
            border-top: 1px solid rgba(255,255,255,0.1);
            text-align: center;
            font-size: 13px;
        }

        /* Responsive Breakpoints */
        @media (max-width: 1024px) {
            .gtmamk-lexicon-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 768px) {
            .gtmamk-hero-grid,
            .gtmamk-lexicon-grid,
            .gtmamk-footer-grid {
                grid-template-columns: 1fr;
            }

            .gtmamk-nav-container {
                flex-direction: column;
                height: auto;
                padding: 16px;
            }

            .gtmamk-menu {
                margin-top: 16px;
                justify-content: center;
                gap: 12px;
            }

            .gtmamk-safety-text {
                padding: 32px;
            }

            .gtmamk-hero {
                padding-top: 180px;
            }
        }