:root {
            --su4j14-primary: #ff8c00;
            --su4j14-primary-dark: #e67e00;
            --su4j14-secondary: #2d3436;
            --su4j14-accent: #0984e3;
            --su4j14-bg-light: #f9f9fb;
            --su4j14-text-main: #2d3436;
            --su4j14-text-muted: #636e72;
            --su4j14-white: #ffffff;
            --su4j14-shadow: 0 10px 30px rgba(0,0,0,0.08);
            --su4j14-radius: 16px;
            --su4j14-container-width: 1280px;
        }

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

        body {
            font-family: "Inter", "Microsoft YaHei", sans-serif;
            color: var(--su4j14-text-main);
            background-color: var(--su4j14-bg-light);
            line-height: 1.7;
            overflow-x: hidden;
        }

        /* Typography */
        h1, h2, h3 {
            line-height: 1.2;
            word-break: keep-all;
            overflow-wrap: break-word;
            margin-bottom: 1.5rem;
        }

        h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 800; }
        h2 { font-size: clamp(1.5rem, 4vw, 2.5rem); font-weight: 700; color: var(--su4j14-secondary); }
        h3 { font-size: clamp(1.2rem, 2vw + 0.5rem, 1.8rem); font-weight: 600; }
        p { margin-bottom: 1rem; word-break: break-word; font-size: clamp(1rem, 0.5vw + 0.8rem, 1.1rem); }

        /* Navigation */
        .su4j14-navbar {
            position: fixed;
            top: 0;
            width: 100%;
            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);
            padding: 1rem 0;
        }

        .su4j14-nav-container {
            max-width: var(--su4j14-container-width);
            margin: 0 auto;
            padding: 0 24px;
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
        }

        .su4j14-logo {
            flex: 0 0 auto;
            min-width: 0;
        }

        .su4j14-logo img {
            height: 40px;
            display: block;
        }

        .su4j14-nav-menu {
            display: flex;
            flex-wrap: wrap;
            list-style: none;
            gap: 1.5rem;
            min-width: 0;
        }

        .su4j14-nav-menu a {
            text-decoration: none;
            color: var(--su4j14-text-main);
            font-weight: 500;
            font-size: 0.95rem;
            transition: color 0.3s ease;
            padding: 0.5rem 0;
            border-bottom: 2px solid transparent;
        }

        .su4j14-nav-menu a:hover,
        .su4j14-nav-menu a.su4j14-active {
            color: var(--su4j14-primary);
            border-bottom-color: var(--su4j14-primary);
        }

        /* Hero Section - Tutorial Header */
        .su4j14-hero {
            padding: 160px 0 80px;
            background: linear-gradient(135deg, #fff 0%, #f0f4f8 100%);
            text-align: center;
            position: relative;
            overflow: hidden;
        }

        .su4j14-hero::before {
            content: '';
            position: absolute;
            top: -10%;
            right: -10%;
            width: 40%;
            height: 60%;
            background: radial-gradient(circle, rgba(255,140,0,0.05) 0%, transparent 70%);
            z-index: 0;
        }

        .su4j14-hero-content {
            max-width: 900px;
            margin: 0 auto;
            padding: 0 24px;
            position: relative;
            z-index: 1;
        }

        .su4j14-hero h1 {
            color: var(--su4j14-secondary);
            margin-bottom: 1.5rem;
        }

        .su4j14-hero p {
            color: var(--su4j14-text-muted);
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 2rem;
        }

        /* Tutorial Steps Section */
        .su4j14-tutorial-section {
            padding: 80px 0;
            max-width: var(--su4j14-container-width);
            margin: 0 auto;
            padding: 80px 24px;
        }

        .su4j14-step-card {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            background: var(--su4j14-white);
            border-radius: var(--su4j14-radius);
            margin-bottom: 64px;
            box-shadow: var(--su4j14-shadow);
            overflow: hidden;
            transition: transform 0.3s ease;
        }

        .su4j14-step-card:hover {
            transform: translateY(-5px);
        }

        .su4j14-step-card:nth-child(even) {
            flex-direction: row-reverse;
        }

        .su4j14-step-image {
            flex: 1 1 500px;
            min-width: 0;
            height: 450px;
        }

        .su4j14-step-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            display: block;
        }

        .su4j14-step-text {
            flex: 1 1 400px;
            padding: 48px;
            min-width: 0;
        }

        .su4j14-step-badge {
            display: inline-block;
            background: var(--su4j14-primary);
            color: white;
            padding: 4px 16px;
            border-radius: 20px;
            font-weight: 700;
            margin-bottom: 1.5rem;
        }

        .su4j14-step-text h3 {
            color: var(--su4j14-secondary);
            margin-bottom: 1rem;
        }

        /* Tech Feature Grid */
        .su4j14-tech-section {
            background: var(--su4j14-secondary);
            color: var(--su4j14-white);
            padding: 96px 24px;
            text-align: center;
        }

        .su4j14-tech-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: 32px;
            max-width: var(--su4j14-container-width);
            margin: 48px auto 0;
        }

        .su4j14-tech-card {
            background: rgba(255, 255, 255, 0.05);
            padding: 40px;
            border-radius: var(--su4j14-radius);
            text-align: left;
            border: 1px solid rgba(255, 255, 255, 0.1);
            transition: background 0.3s ease;
        }

        .su4j14-tech-card:hover {
            background: rgba(255, 255, 255, 0.1);
        }

        .su4j14-tech-card h4 {
            color: var(--su4j14-primary);
            font-size: 1.4rem;
            margin-bottom: 1rem;
        }

        .su4j14-tech-benefit {
            margin-top: 1.5rem;
            padding-top: 1.5rem;
            border-top: 1px dashed rgba(255, 255, 255, 0.2);
            font-style: italic;
            color: #bdc3c7;
        }

        /* Tier Architecture Section */
        .su4j14-tier-section {
            padding: 96px 24px;
            max-width: var(--su4j14-container-width);
            margin: 0 auto;
        }

        .su4j14-tier-header {
            text-align: center;
            margin-bottom: 64px;
        }

        .su4j14-tier-container {
            display: flex;
            flex-wrap: wrap;
            gap: 24px;
            justify-content: center;
        }

        .su4j14-tier-card {
            flex: 1 1 350px;
            min-width: 0;
            background: var(--su4j14-white);
            border-radius: var(--su4j14-radius);
            padding: 40px;
            box-shadow: var(--su4j14-shadow);
            border-top: 5px solid var(--su4j14-primary);
        }

        .su4j14-tier-card.featured {
            transform: scale(1.05);
            border-top-color: var(--su4j14-accent);
        }

        .su4j14-tier-name {
            font-size: 1.5rem;
            font-weight: 800;
            margin-bottom: 0.5rem;
        }

        .su4j14-tier-user {
            color: var(--su4j14-text-muted);
            margin-bottom: 2rem;
            font-weight: 600;
        }

        .su4j14-feature-list {
            list-style: none;
            margin-bottom: 2.5rem;
        }

        .su4j14-feature-list li {
            padding: 10px 0;
            border-bottom: 1px solid #eee;
            font-size: 0.95rem;
        }

        .su4j14-feature-list li::before {
            content: "✓";
            color: var(--su4j14-primary);
            margin-right: 10px;
            font-weight: bold;
        }

        /* Footer */
        .su4j14-footer {
            background: #1a1a1a;
            color: #999;
            padding: 80px 24px 40px;
        }

        .su4j14-footer-grid {
            max-width: var(--su4j14-container-width);
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 48px;
            margin-bottom: 64px;
        }

        .su4j14-footer-brand h2 {
            color: var(--su4j14-white);
            margin-bottom: 1.5rem;
        }

        .su4j14-footer-bottom {
            max-width: var(--su4j14-container-width);
            margin: 0 auto;
            padding-top: 40px;
            border-top: 1px solid #333;
            text-align: center;
            font-size: 0.9rem;
        }

        /* Responsive Adjustments */
        @media (max-width: 1024px) {
            .su4j14-tier-card.featured {
                transform: none;
            }
        }

        @media (max-width: 768px) {
            .su4j14-nav-menu {
                display: none; /* Mobile menu logic omitted for brevity, would usually be a hamburger */
            }
            .su4j14-step-card {
                flex-direction: column !important;
            }
            .su4j14-step-image {
                flex: 0 0 300px;
                width: 100%;
            }
            .su4j14-step-text {
                padding: 32px 24px;
            }
            .su4j14-hero {
                padding: 120px 0 60px;
            }
        }