:root {
            --h0u505-primary: #4285F4;
            --h0u505-red: #EA4335;
            --h0u505-yellow: #FBBC05;
            --h0u505-green: #34A853;
            --h0u505-text-dark: #202124;
            --h0u505-text-light: #5f6368;
            --h0u505-bg-gray: #f8f9fa;
            --h0u505-white: #ffffff;
            --h0u505-max-width: 1400px;
            --h0u505-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

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

        body {
            font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
            color: var(--h0u505-text-dark);
            line-height: 1.6;
            background-color: var(--h0u505-white);
            overflow-x: hidden;
            word-break: break-word;
        }

        /* Navigation */
        .h0u505-header {
            position: sticky;
            top: 0;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: blur(10px);
            z-index: 1000;
            box-shadow: 0 2px 10px rgba(0,0,0,0.05);
            width: 100%;
        }

        .h0u505-nav-container {
            max-width: var(--h0u505-max-width);
            margin: 0 auto;
            padding: 0 24px;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: space-between;
            height: 72px;
        }

        .h0u505-logo {
            display: flex;
            align-items: center;
            min-width: 0;
        }

        .h0u505-logo img {
            height: 32px;
            width: auto;
        }

        .h0u505-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 16px;
            min-width: 0;
        }

        .h0u505-menu-item a {
            text-decoration: none;
            color: var(--h0u505-text-light);
            font-weight: 500;
            font-size: 14px;
            padding: 8px 12px;
            border-radius: 4px;
            transition: var(--h0u505-transition);
            white-space: nowrap;
        }

        .h0u505-menu-item a:hover {
            color: var(--h0u505-primary);
            background: rgba(66, 133, 244, 0.05);
        }

        .h0u505-menu-item a.h0u505-active {
            color: var(--h0u505-primary);
            position: relative;
        }

        .h0u505-menu-item a.h0u505-active::after {
            content: "";
            position: absolute;
            bottom: -22px;
            left: 0;
            width: 100%;
            height: 3px;
            background: var(--h0u505-primary);
            border-radius: 3px 3px 0 0;
        }

        /* Hero Section */
        .h0u505-hero {
            padding: 96px 24px;
            background: radial-gradient(circle at 80% 20%, rgba(66, 133, 244, 0.05), transparent 40%),
                        radial-gradient(circle at 20% 80%, rgba(52, 168, 83, 0.05), transparent 40%);
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            align-items: center;
            overflow: hidden;
        }

        .h0u505-hero-content {
            flex: 1;
            min-width: 320px;
            max-width: 600px;
            padding-right: 48px;
        }

        .h0u505-hero-title {
            font-size: clamp(2.5rem, 5vw, 4rem);
            line-height: 1.1;
            font-weight: 700;
            margin-bottom: 24px;
            color: var(--h0u505-text-dark);
            word-break: keep-all;
        }

        .h0u505-hero-subtitle {
            font-size: clamp(1.1rem, 2vw, 1.4rem);
            color: var(--h0u505-text-light);
            margin-bottom: 40px;
            line-height: 1.5;
        }

        .h0u505-hero-image {
            flex: 1;
            min-width: 320px;
            max-width: 700px;
            position: relative;
        }

        .h0u505-hero-image img {
            width: 100%;
            height: auto;
            border-radius: 24px;
            box-shadow: 0 30px 60px rgba(0,0,0,0.12);
            transition: var(--h0u505-transition);
        }

        .h0u505-hero-image:hover img {
            transform: translateY(-10px);
        }

        /* Download Primary Box */
        .h0u505-download-panel {
            background: var(--h0u505-white);
            padding: 40px;
            border-radius: 24px;
            box-shadow: 0 4px 24px rgba(0,0,0,0.06);
            display: inline-block;
            width: 100%;
            max-width: 500px;
        }

        .h0u505-btn-primary {
            display: inline-block;
            background: var(--h0u505-primary);
            color: white;
            padding: 18px 48px;
            border-radius: 50px;
            font-size: 1.2rem;
            font-weight: 600;
            text-decoration: none;
            transition: var(--h0u505-transition);
            box-shadow: 0 4px 15px rgba(66, 133, 244, 0.3);
            text-align: center;
            width: 100%;
        }

        .h0u505-btn-primary:hover {
            background: #3367d6;
            transform: scale(1.02);
            box-shadow: 0 6px 20px rgba(66, 133, 244, 0.4);
        }

        .h0u505-download-meta {
            margin-top: 16px;
            font-size: 13px;
            color: var(--h0u505-text-light);
            text-align: center;
        }

        /* Grid Layout: Security Matrix */
        .h0u505-section {
            padding: 96px 24px;
            max-width: var(--h0u505-max-width);
            margin: 0 auto;
        }

        .h0u505-section-title {
            text-align: center;
            font-size: clamp(1.8rem, 3vw, 2.5rem);
            margin-bottom: 64px;
        }

        .h0u505-security-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: 32px;
        }

        .h0u505-card {
            background: var(--h0u505-bg-gray);
            padding: 40px;
            border-radius: 20px;
            border: 1px solid transparent;
            transition: var(--h0u505-transition);
        }

        .h0u505-card:hover {
            background: var(--h0u505-white);
            border-color: var(--h0u505-primary);
            box-shadow: 0 10px 30px rgba(0,0,0,0.05);
        }

        .h0u505-card-tag {
            display: inline-block;
            padding: 4px 12px;
            background: rgba(66, 133, 244, 0.1);
            color: var(--h0u505-primary);
            border-radius: 4px;
            font-size: 12px;
            font-weight: 700;
            margin-bottom: 16px;
            text-transform: uppercase;
        }

        .h0u505-card-title {
            font-size: 1.5rem;
            margin-bottom: 16px;
            color: var(--h0u505-text-dark);
        }

        .h0u505-card-text {
            color: var(--h0u505-text-light);
            font-size: 1rem;
            line-height: 1.7;
        }

        /* Installer Guide Section */
        .h0u505-guide-section {
            background-color: var(--h0u505-bg-gray);
            width: 100%;
        }

        .h0u505-guide-container {
            max-width: var(--h0u505-max-width);
            margin: 0 auto;
            padding: 96px 24px;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 64px;
        }

        .h0u505-guide-img {
            flex: 1;
            min-width: 320px;
        }

        .h0u505-guide-img img {
            width: 100%;
            border-radius: 16px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.08);
        }

        .h0u505-guide-steps {
            flex: 1;
            min-width: 320px;
        }

        .h0u505-step {
            display: flex;
            margin-bottom: 32px;
            gap: 24px;
        }

        .h0u505-step-num {
            width: 48px;
            height: 48px;
            background: var(--h0u505-primary);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            flex-shrink: 0;
        }

        /* Timeline Section */
        .h0u505-vision-section {
            padding: 96px 24px;
            text-align: center;
        }

        .h0u505-timeline {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 24px;
            margin-top: 48px;
        }

        .h0u505-timeline-item {
            flex: 1;
            min-width: 280px;
            max-width: 350px;
            padding: 32px;
            background: #fff;
            border-top: 4px solid var(--h0u505-primary);
            box-shadow: 0 4px 20px rgba(0,0,0,0.05);
            border-radius: 0 0 12px 12px;
            text-align: left;
        }

        .h0u505-timeline-year {
            font-size: 2rem;
            font-weight: 800;
            color: var(--h0u505-primary);
            margin-bottom: 8px;
        }

        /* Offline Block */
        .h0u505-offline-block {
            margin: 96px auto;
            max-width: 1100px;
            background: linear-gradient(135deg, #202124 0%, #3c4043 100%);
            border-radius: 32px;
            padding: 64px;
            color: white;
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 48px;
        }

        .h0u505-offline-content {
            flex: 1;
            min-width: 300px;
        }

        .h0u505-offline-image {
            flex: 1;
            min-width: 300px;
        }

        .h0u505-offline-image img {
            width: 100%;
            border-radius: 12px;
            opacity: 0.9;
        }

        /* Footer */
        .h0u505-footer {
            background: var(--h0u505-bg-gray);
            padding: 64px 24px;
            border-top: 1px solid #e0e0e0;
        }

        .h0u505-footer-container {
            max-width: var(--h0u505-max-width);
            margin: 0 auto;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 48px;
        }

        .h0u505-footer-brand h2 {
            font-size: 24px;
            margin-bottom: 16px;
            color: var(--h0u505-text-dark);
        }

        .h0u505-footer-links {
            display: flex;
            flex-wrap: wrap;
            gap: 64px;
        }

        .h0u505-footer-col h4 {
            margin-bottom: 24px;
            font-size: 14px;
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        .h0u505-footer-col ul {
            list-style: none;
        }

        .h0u505-footer-col li {
            margin-bottom: 12px;
        }

        .h0u505-footer-col a {
            text-decoration: none;
            color: var(--h0u505-text-light);
            font-size: 14px;
            transition: var(--h0u505-transition);
        }

        .h0u505-footer-col a:hover {
            color: var(--h0u505-primary);
        }

        .h0u505-footer-bottom {
            max-width: var(--h0u505-max-width);
            margin: 48px auto 0;
            padding-top: 24px;
            border-top: 1px solid #e0e0e0;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            font-size: 12px;
            color: var(--h0u505-text-light);
        }

        /* Responsive Breakpoints */
        @media (max-width: 992px) {
            .h0u505-hero { padding: 64px 24px; }
            .h0u505-hero-content { padding-right: 0; text-align: center; margin-bottom: 48px; }
            .h0u505-download-panel { margin: 0 auto; }
        }

        @media (max-width: 768px) {
            .h0u505-nav-container { height: auto; padding: 16px; }
            .h0u505-menu { width: 100%; order: 3; margin-top: 16px; justify-content: center; }
            .h0u505-hero-title { font-size: 2.2rem; }
            .h0u505-offline-block { padding: 32px; }
            .h0u505-footer-links { gap: 32px; }
        }