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

        html, body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
            color: #333;
            line-height: 1.6;
            background-color: #f5f7fa;
        }

        .gcs5s-header-wrapper {
            background: linear-gradient(135deg, #ffffff 0%, #f9f9f9 100%);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            position: sticky;
            top: 0;
            z-index: 1000;
        }

        .gcs5s-header-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 70px;
        }

        .gcs5s-logo-section {
            display: flex;
            align-items: center;
            gap: 12px;
            text-decoration: none;
            color: #333;
        }

        .gcs5s-logo-section img {
            height: 40px;
            width: auto;
        }

        .gcs5s-brand-name {
            font-size: 18px;
            font-weight: 600;
            color: #0066cc;
        }

        .gcs5s-nav-menu {
            display: flex;
            gap: 30px;
            align-items: center;
        }

        .gcs5s-nav-link {
            text-decoration: none;
            color: #333;
            font-size: 14px;
            font-weight: 500;
            transition: color 0.3s ease;
            padding: 8px 0;
            border-bottom: 2px solid transparent;
        }

        .gcs5s-nav-link:hover {
            color: #0066cc;
            border-bottom-color: #0066cc;
        }

        .gcs5s-banner-section {
            background: linear-gradient(135deg, #0066cc 0%, #0052a3 100%);
            color: white;
            padding: 80px 20px;
            text-align: center;
        }

        .gcs5s-banner-content {
            max-width: 1200px;
            margin: 0 auto;
        }

        .gcs5s-banner-title {
            font-size: 48px;
            font-weight: 700;
            margin-bottom: 20px;
            line-height: 1.3;
        }

        .gcs5s-banner-subtitle {
            font-size: 18px;
            margin-bottom: 30px;
            opacity: 0.95;
            line-height: 1.5;
        }

        .gcs5s-banner-buttons {
            display: flex;
            gap: 15px;
            justify-content: center;
            flex-wrap: wrap;
        }

        .gcs5s-btn-primary {
            background-color: #ff6b35;
            color: white;
            padding: 14px 35px;
            border: none;
            border-radius: 4px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(255, 107, 53, 0.3);
        }

        .gcs5s-btn-primary:hover {
            background-color: #ff5520;
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(255, 107, 53, 0.4);
        }

        .gcs5s-btn-secondary {
            background-color: transparent;
            color: white;
            padding: 14px 35px;
            border: 2px solid white;
            border-radius: 4px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            transition: all 0.3s ease;
        }

        .gcs5s-btn-secondary:hover {
            background-color: rgba(255, 255, 255, 0.1);
        }

        .gcs5s-main-content {
            max-width: 1200px;
            margin: 60px auto;
            padding: 0 20px;
        }

        .gcs5s-section-title {
            font-size: 32px;
            font-weight: 700;
            color: #333;
            margin-bottom: 40px;
            text-align: center;
            position: relative;
            padding-bottom: 20px;
        }

        .gcs5s-section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 4px;
            background-color: #0066cc;
            border-radius: 2px;
        }

        .gcs5s-features-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 30px;
            margin-bottom: 60px;
        }

        .gcs5s-feature-card {
            background: white;
            padding: 30px;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            transition: all 0.3s ease;
            text-align: center;
        }

        .gcs5s-feature-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
        }

        .gcs5s-feature-icon {
            font-size: 40px;
            margin-bottom: 20px;
        }

        .gcs5s-feature-title {
            font-size: 18px;
            font-weight: 600;
            color: #333;
            margin-bottom: 12px;
        }

        .gcs5s-feature-text {
            font-size: 14px;
            color: #666;
            line-height: 1.6;
        }

        .gcs5s-download-section {
            background: white;
            padding: 50px;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            margin-bottom: 60px;
        }

        .gcs5s-download-title {
            font-size: 24px;
            font-weight: 700;
            color: #333;
            margin-bottom: 20px;
        }

        .gcs5s-download-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-bottom: 30px;
        }

        .gcs5s-download-item {
            border: 1px solid #e0e0e0;
            padding: 20px;
            border-radius: 6px;
            text-align: center;
            transition: all 0.3s ease;
        }

        .gcs5s-download-item:hover {
            border-color: #0066cc;
            background-color: #f9f9f9;
        }

        .gcs5s-download-platform {
            font-size: 16px;
            font-weight: 600;
            color: #333;
            margin-bottom: 10px;
        }

        .gcs5s-download-version {
            font-size: 12px;
            color: #999;
            margin-bottom: 15px;
        }

        .gcs5s-download-btn {
            background-color: #0066cc;
            color: white;
            padding: 10px 20px;
            border: none;
            border-radius: 4px;
            font-size: 14px;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            transition: background-color 0.3s ease;
        }

        .gcs5s-download-btn:hover {
            background-color: #0052a3;
        }

        .gcs5s-about-section {
            background: white;
            padding: 50px;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            margin-bottom: 60px;
        }

        .gcs5s-about-title {
            font-size: 24px;
            font-weight: 700;
            color: #333;
            margin-bottom: 20px;
        }

        .gcs5s-about-text {
            font-size: 15px;
            color: #666;
            line-height: 1.8;
            margin-bottom: 15px;
        }

        .gcs5s-highlight {
            color: #0066cc;
            font-weight: 600;
        }

        .gcs5s-cta-section {
            background: linear-gradient(135deg, #0066cc 0%, #0052a3 100%);
            color: white;
            padding: 60px 20px;
            text-align: center;
            border-radius: 8px;
            margin-bottom: 60px;
        }

        .gcs5s-cta-title {
            font-size: 32px;
            font-weight: 700;
            margin-bottom: 20px;
        }

        .gcs5s-cta-text {
            font-size: 16px;
            margin-bottom: 30px;
            opacity: 0.95;
        }

        .gcs5s-cta-button {
            background-color: #ff6b35;
            color: white;
            padding: 14px 40px;
            border: none;
            border-radius: 4px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            display: inline-block;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(255, 107, 53, 0.3);
        }

        .gcs5s-cta-button:hover {
            background-color: #ff5520;
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(255, 107, 53, 0.4);
        }

        .gcs5s-support-section {
            background: white;
            padding: 50px;
            border-radius: 8px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
            margin-bottom: 60px;
        }

        .gcs5s-support-title {
            font-size: 24px;
            font-weight: 700;
            color: #333;
            margin-bottom: 30px;
        }

        .gcs5s-support-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
        }

        .gcs5s-support-item {
            text-align: center;
            padding: 20px;
        }

        .gcs5s-support-icon {
            font-size: 32px;
            margin-bottom: 15px;
        }

        .gcs5s-support-name {
            font-size: 16px;
            font-weight: 600;
            color: #333;
            margin-bottom: 10px;
        }

        .gcs5s-support-info {
            font-size: 14px;
            color: #666;
            word-break: break-all;
        }

        .gcs5s-support-link {
            color: #0066cc;
            text-decoration: none;
            transition: color 0.3s ease;
        }

        .gcs5s-support-link:hover {
            color: #0052a3;
            text-decoration: underline;
        }

        .gcs5s-footer-wrapper {
            background-color: #1a1a1a;
            color: #ccc;
            padding: 40px 20px 20px;
            margin-top: 60px;
        }

        .gcs5s-footer-content {
            max-width: 1200px;
            margin: 0 auto;
        }

        .gcs5s-footer-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 30px;
            margin-bottom: 30px;
            padding-bottom: 30px;
            border-bottom: 1px solid #333;
        }

        .gcs5s-footer-section-title {
            font-size: 14px;
            font-weight: 700;
            color: white;
            margin-bottom: 15px;
            text-transform: uppercase;
        }

        .gcs5s-footer-link {
            display: block;
            font-size: 13px;
            color: #ccc;
            text-decoration: none;
            margin-bottom: 8px;
            transition: color 0.3s ease;
        }

        .gcs5s-footer-link:hover {
            color: #0066cc;
        }

        .gcs5s-footer-bottom {
            text-align: center;
            font-size: 13px;
            color: #999;
            padding: 20px 0;
        }

        .gcs5s-footer-copyright {
            margin-bottom: 8px;
        }

        @media (max-width: 768px) {
            .gcs5s-banner-title {
                font-size: 32px;
            }

            .gcs5s-banner-subtitle {
                font-size: 16px;
            }

            .gcs5s-section-title {
                font-size: 24px;
            }

            .gcs5s-nav-menu {
                gap: 15px;
                font-size: 12px;
            }

            .gcs5s-banner-buttons {
                flex-direction: column;
                align-items: center;
            }

            .gcs5s-btn-primary,
            .gcs5s-btn-secondary {
                width: 100%;
                max-width: 300px;
            }

            .gcs5s-download-section,
            .gcs5s-about-section,
            .gcs5s-support-section {
                padding: 30px;
            }

            .gcs5s-header-container {
                height: auto;
                flex-wrap: wrap;
                padding: 15px 20px;
            }

            .gcs5s-nav-menu {
                width: 100%;
                margin-top: 15px;
                flex-wrap: wrap;
            }
        }

        @media (max-width: 480px) {
            .gcs5s-banner-title {
                font-size: 24px;
            }

            .gcs5s-banner-section {
                padding: 50px 20px;
            }

            .gcs5s-section-title {
                font-size: 20px;
            }

            .gcs5s-cta-title {
                font-size: 24px;
            }
        }